题目内容

As time went by, they found their efforts to help students ________．

[　　]

A．

showed off

B．

took off

C．

put off

D．

paid off

答案：D

练习册系列答案

相关题目

As time ________, we found Jack was honest．

[　　]

A．went by

B．went away

C．got through

D．made up

One genetic mutation(基因突变)occurs on average for every 15 cigarettes that a typical lung-cancer patient smokes, according to a study that has found for the first time all of the mutations happen during the lifetime of a cancer patient.

Scientists have completed a full genetic examinations of the genomes（基因组） of cancer patients, and hope the information will lead to a basic understanding of the causes of cancer—and possibly drugs and treatments—by making out the mutations that turn a healthy cell into a cancerous tumor cell.

They studied a lung-cancer patient who had about 23,000 DNA mutations in his lung cells that were connected with exposure(暴露) to the toxins found in cigarette smoke and had built up over his lifetime.

They also looked at a patient with malignant melanoma(恶性黑色肿瘤), the most dangerous form of skin cancer, who had got 30,000 special mutations known to be connected with exposure to sunlight.

Scientists believe this new finding into the genetics of cancer will finally lead to new drugs and perfect treatments that aim at the specific changes to the gene that cause the disease, as well as new techniques for discovering following cancers that have escaped from treatment in other parts of the body.

“For the first time, we have a complete map of all mutations in a cancer cell,” said Dr. Peter Campbell, who led the Cancer Genome project to work out the whole DNA system of tumor cells in order find the mutations.

A similar method was performed on the cells of a patient with skin cancer, which is how the researchers were able to show that the malignant skin cells contained changes that resulted from exposure to light.

“These are the two main cancers in the developed world for which we know the chief exposure. For lung cancer it is cigarette smoke, and for malignant melanoma it is exposure to sunlight,” Professor Campbell said.

1.What can the genetic examination of the genomes of cancer patients be used for?

A.To help the professors to win the Nobel Prizes.

B.To advance the study of reason and cure of cancer.

C.To make the medicine industries earn more money.

D.To help the cancer patients reduce their pain.

2.The underlined word in the third paragraph can be placed by_____.

A.smoke B.sunlight C.cell D.poison

3.Which of the following statements is right according to the passage?

A.The lung-cancer patient had 30,000 mutations in his lung cells.

B.The genetics of cancer will finally lead to new drugs soon.

C.It’s the first time that people mapped mutations in a cancer cell.

D.Dr. Peter tries to invent a new drug with the DNA system.

4.What’s the similarity between malignant melanoma and skin cancer of patients?

A.Their smoking too much in daily life.

B.Their receiving too much sunshine.

C.Their refusing to accept treatment.

D.Their interest in travelling abroad.

Between their crazy schedules and upside-down circadian（昼夜节律的） rhythms, teens have always been somewhat sleep-deprived（剥夺）．Now technology is making it worse．

Teens are not just texting, instant-messaging and surfing Facebook all day; they’re sleeping with their cell phones or laptops, too．Or rather, not sleeping．And doctors and parents, many of whom raised in an era when phones were attached to walls, are concerned．

“So many teens are having sleep issues, and parents aren’t necessarily regulating the use of the electronic devices enough,” says Margie Ryerson, a therapist．“It’s impossible to wind down and relax the body, the mind, the senses and be ready to fall asleep．”

“We all know teens don’t get enough sleep in general,” says San Francisco．“As long as parents allow teens to have these devices in their bedrooms at night, teens will be tempted（诱惑） to use them．”… Teens would socialize 24/7 if they could．

Ryerson calls it the CNN syndrome of teenhood— round-the-clock reports on breaking news about everything, from homework to wardrobe choices to ice-cream cravings．

Sleep deprivation is linked to memory and concentration problems, anxiety and depression, and moodiness．“Many people assume these problems arise directly from adolescence, which is not really true,” he says．“The real issue is sleep deprivation．Late-night texting can certainly make the situation worse．”

“The psychology behind this constant contact is certainly understandable,” Ryerson says．“It comes from wanting to avoid being left out．They won’t be considered important and significant in their peer group, if they don’t know what’s going on．If they’re on top of everything, they belong,” she says．

“What helps, at least for younger kids,” says Ryerson, “is parental involvement．If all of their friends are all able to text into the early hours of the night, it is hard for a middle or high schooler to set the limit themselves．Often they appreciate parents stepping in．”

“As parents, we want our kids to be happy, healthy and responsible,” she says, “and the most necessary requirement for achieving balance is to first take care of ourselves physically — eating well, exercising and getting enough sleep．”

1.According to Ryerson, it seems that ____．

A．it is unnecessary to control teens’ using the electric devices

B．parents possibly don’t control teens in using the electric devices

C．there is no need for parents to make use of the electric devices

D．parents don’t learn enough how to use the electric devices

2.By saying the underlined part “the CNN syndrome of teenhood”（in Para5）, Ryerson means _．

A．teens are affected by CNN news reports very much

B．teens watch news report on CNN around the clock

C．teens text to tell each other everything possible

D．teens like the news report on CNN

3.When teens felt depressed, people used to think it was because ____．

A．teens stayed up late to do homework

B．teens were easily anxious in character

C．teens didn’t have enough sleep at night

D．teens were going through a period of growth

4.Why do teens keep texting all the time?

A．To have a sense of being accepted by others．

B．To keep informed of what is going on in the world．

C．To spread important news among their group．

D．To reduce the pressure from parents and schools．

Height is just one of the thousands of features your genes(基因)decide. In fact, because you have two parents, your genes provide you a height that usually lands somewhere between the height of each parent. If both your parents are tall, then most probably you will be tall, too, but if you have questions about how tall you're going to be, ask your doctor if he or she can help you find it out.

But genes don't decide everything. For example, eating an unhealthy diet can keep you from growing to your full potential(潜力). Getting plenty of sleep and enough exercise will help you grow to the expected height.

No doubt(怀疑) you're wondering how fast you should grow. It depends. There's no perfect or right answer. Generally speaking, kids grow about 2 inches (6 centimeters) a year between age 3 and the time when they start puberty (when your body starts changing and becoming more grown up).

Your doctor will know how your growth has been going over the years. Two centimeters here and 2 inches there are not nearly as important as the height you're at now, how you've been growing up to this point, and what other changes your body may be going through.

Don't be scared if you seem to have grown a lot in a very short time. Everyone has a growth spurt（高峰）during puberty. The age for starting puberty is about 10 for girls and about 11 for boys. But it can be earlier or later ——between 7 and 13 for girls and 9 and 15 for boys.

You'll usually begin to notice that you're growing faster about a year or so after your body starts to show the first changes of puberty.

1.If you want to know how fast and how tall you should grow, ____________.

A. you should have enough exercise B. you can ask doctors for help

C. you should save the environment D. You can record your growth during puberty

2. This passage is mainly about ____________.

A. how the genes work in your body B. when is the time you grow fast

C. why you look like your parents D. how you grow to a certain height

3. After reading this passage, we can explain ___________.

A. how good it is to be a doctor B. how much sleep time we need

C. why genes can’t decide everything D. what healthy diet is

4. Which is NOT mentioned in the passage?

A. Your height most probably depends on how high your parents are.

B. Girls’ age for starting puberty is usually earlier than that for boys’.

C. The time showing the first changes of puberty is never noticed.

D. You may be scared sometimes when you grow too fast.

As time ________, we found Jack was honest．

A.
went by
B.
went away
C.
got through
D.
made up

As time ________, we found Jack was honest．

试题分类