题目内容
Now lots of parks are free of ________, and you can go in at any time.
- A.money
- B.payment
- C.cash
- D.charge
Dear Kind-Trustee-Who-Sends-Orphans-to-College,
Here I am! I traveled yesterday for four hours in a train．It’s a funny feeling, isn’t it? I never rode in one before．
College is the biggest, most puzzling place—I get lost whenever I leave my room. I will write you a description later when I'm feeling less confused; also I will tell you about my lessons. Classes don't begin until Monday morning, and this is Saturday night. But I wanted to write a letter first just to get acquainted.
It seems strange to be writing letters to somebody you don't know. It seems strange for me to be writing letters at all—I've never written more than three or four in my life, so please overlook it if these are not a model kind.
Before leaving yesterday morning, Mrs. Lippett and I had a very serious talk. She told me how to behave all the rest of my life, and especially how to behave towards the kind gentleman who is doing so much for me. I must take care to be very respectful.
But how can one be very respectful to a person who wishes to be called John Smith? Why couldn't you have picked out a name with a little personality? I might as well write letters to Dear Flagpole or Dear Clothes-line.
I have been thinking about you a great deal this summer; having somebody take an interest in me after all these years makes me feel as though I had found a sort of family. It seems as though I belonged to somebody now, and it's a very comfortable feeling. I must say, however, that when I think about you, my imagination has very little to work upon. There are just three things that I know: I, You are tall. Ⅱ. You are rich. Ⅲ. You hate girls.
I suppose I might call you Dear Mr. Girl-Hater. Only that's rather rude to me. Or Dear Mr. Rich-Man, but that's rude to you, as though money were the only important thing about you. Besides, being rich is such a very external quality. Maybe you won't stay rich all your life; lots of very clever men get broke in Wall Street. But at least you will stay tall all your life! So I've decided to call you Dear Daddy-Long-Legs. I hope you won't mind. It's just a private pet name we won't tell Mrs. Lippett.
The ten o'clock bell is going to ring in two minutes. Our day is divided into sections by bells. We eat and sleep and study by bells. It's very lifeful. There it goes! Lights out. Good night.
Observe how precisely I obey rules--due to my training in the John Grier Home.
Yours most respectfully,
Jerusha Abbott
to Mr. Daddy-Long-Legs Smith
【小题1】Jerusha felt “confused” because ______.
| A．she had never written to the trustee before |
| B．she was not familiar with the college yet |
| C．she could never find the way to her home |
| D．she had never traveled on a train berore |
| A．he was a total stranger to her |
| B．she was sure it was a false identity |
| C．the name was too common |
| D．nobody would like to be called that name |
| A．busy | B．restricted by rules | C．pressed for time | D．full of energy |
| A．in order to show her respect for him |
| B．because it was one of his inner quality |
| C．in older to make them feel closer to each other |
| D．because she had always wanted a father |
Medical drugs sometimes cause more damage than they cure. One solution to this problem is to put the drugs inside a capsule, protecting them from the body—and the body from them—until they can be released at just the right spot. There are lots of ways to trigger(引发) this release, including changing temperature, acidity, and so on. But triggers can come with their own risks—burns, for example. Now, researchers in California have designed what could be a harmless trigger to date: shining near-infrared light (NIR,近红外线) on the drug in the capsule.
The idea of using light to liberate the drug in the capsule isn't new. Researchers around the globe have developed polymers (聚合物) and other materials that begin to break down when they absorb either ultraviolet (UV,紫外线) or visible light. But tissues also readily absorb UV and visible light, which means the drug release can be triggered only near the skin, where the light can reach the capsule. NIR light largely passes through tissues, so researchers have tried to use it as a trigger. But few compounds(化合物) absorb NIR well and go through chemical changes.
That changed last year when Adah Almutairi, a chemist at the University of California, San Diego, reported that she and her colleagues had designed a polymer that breaks down when it absorbs NIR light. Their polymer used a commercially available NIR-absorbing group called o-nitrobenzyl (ONB). When they catch the light, ONB groups fall off the polymer, leading to its breakdown. But ONB is only a so-so NIR absorber, and it could be poisonous to cells when it separates from the polymer.
So Almutairi and her colleagues reported creating a new material for capsules that's even better. This one consists of a long chain of compounds called cresol groups linked in a polymer. Cresol contains reactive(易反应的) components that make it highly unstable in its polymeric form, a feature Almutairi and her colleagues use to their advantage. After polymerizing the cresols, they cap each reactive component with a light-absorbing compound called Bhc. When the Bhcs absorb NIR light, the reactive groups are exposed and break the long polymer into two short chains. Shining additional light continues this breakdown, potentially releasing any drugs in the capsule. What's more, Almutairi says, Bhc is 10 times better at absorbing NIR than is ONB and is not poisonous to cells.
【小题1】According to the passage, which of the following could be the best trigger?
| A．Temperature change. | B．NIR light. | C．Acidity change. | D．UV light. |
| A． It breaks down when it absorbs NIR light. |
| B． It falls off the polymer and triggers drug release. |
| C． It has not come onto the market up till now. |
| D． It is not effective enough and could be poisonous. |
| A．protected | B．formed | C．exposed | D．combined |