BEING an astronaut sounds cool, doesn't it? In space, they get to do some pretty amazing things, like floating in zero gravity(重力).
However, there are also plenty of things that astronauts can't do because of their weightless environment, and that's very sad. What's worse, they can't even let their sadness show, because it's impossible to cry in zero gravity.
Of course, astronauts can still produce tears. But crying is much more difficult in space, according to The Atlantic(大西洋月刊) in January. Without gravity, tears don't flow(流动) down out of the eyes like they do here on Earth. This means that when you cry in space, your tears have nowhere to go-they just stick(粘) to your eyes.
In May 2011, astronaut Andrew Feustel experienced this during one of his spacewalks. "Tears," he said, "don't fall off of your eyes...They just kind of stay there."
Besides making your vision(视线)unclear, this can also cause physical pain. Back on Earth, tears are supposed to bring comfort to the eyes. But that's not the case in space. The space environment dries out astronauts' eyes, and when tears suddenly wet the eyes, it can cause pain rather than comfort. "My right eye is stinging(刺痛) like crazy," Feustel told his teammate during the walk.
Since gravity doesn't work in space, astronauts need some extra help to get rid of（除去） the tears. Feustel chose to rub his eyes against his helmet to wipe(擦) the tears away. Another choice is to just wait-"When the tears get big enough they simply break free of the eyes and float around," astronaut Ron Parise told The Atlantic.
There are lots of small things-things like crying-that we are so used to on Earth. We usually take them for granted until they become a problem in a totally different environment, like space.  There, astronauts can't talk to each other directly. They also can't eat or drink in normal ways. They can't even burp (打嗝), because there is no gravity to hold the food down in their stomach. If they do burp, they just end up throwing up（呕吐）everything in their stomach, according to the UK National Space Center.
Therefore, perhaps it's only space explorers who can honestly say: "Gravity, you're the best."
【小题1】From Paragraphs 2 and 3 , we can know that_______.

BEING an astronaut sounds cool, doesn't it? In space, they get to do some pretty amazing things, like floating in zero gravity(重力).

However, there are also plenty of things that astronauts can't do because of their weightless environment, and that's very sad. What's worse, they can't even let their sadness show, because it's impossible to cry in zero gravity.

Of course, astronauts can still produce tears. But crying is much more difficult in space, according to The Atlantic(大西洋月刊) in January. Without gravity, tears don't flow(流动) down out of the eyes like they do here on Earth. This means that when you cry in space, your tears have nowhere to go-they just stick(粘) to your eyes.

In May 2011, astronaut Andrew Feustel experienced this during one of his spacewalks. "Tears," he said, "don't fall off of your eyes...They just kind of stay there."

Besides making your vision(视线)unclear, this can also cause physical pain. Back on Earth, tears are supposed to bring comfort to the eyes. But that's not the case in space. The space environment dries out astronauts' eyes, and when tears suddenly wet the eyes, it can cause pain rather than comfort. "My right eye is stinging(刺痛) like crazy," Feustel told his teammate during the walk.

Since gravity doesn't work in space, astronauts need some extra help to get rid of（除去） the tears. Feustel chose to rub his eyes against his helmet to wipe(擦) the tears away. Another choice is to just wait-"When the tears get big enough they simply break free of the eyes and float around," astronaut Ron Parise told The Atlantic.

There are lots of small things-things like crying-that we are so used to on Earth. We usually take them for granted until they become a problem in a totally different environment, like space.  There, astronauts can't talk to each other directly. They also can't eat or drink in normal ways. They can't even burp (打嗝), because there is no gravity to hold the food down in their stomach. If they do burp, they just end up throwing up（呕吐）everything in their stomach, according to the UK National Space Center.

Therefore, perhaps it's only space explorers who can honestly say: "Gravity, you're the best."

1.From Paragraphs 2 and 3 , we can know that_______.

A．astronauts are unable to feel sad in space

B．astronauts produce fewer tears in space

C．tears produced in space flow down more slowly

D．tears produced in space don't flow downward

2.What effect do tears have on astronauts?

A．They cause physical pain.

B．They bring comfort to them.

C．They make their vision clearer.

D．They float around and cause trouble.

3.The underlined phrase "take them for granted" in paragraph 7 means _______.

A．find them important

B．consider them useless

C．need them during an emergency

D．fail to notice their presence(存在)

4.The second-to-last paragraph (paragraph 7) is mainly about_______.

A．suggestions of how astronauts can stay comfortable in space

B．other basic things that are difficult to do in space

C．why burping is impossible in space

D．things human can't do without gravity

If you are lost in the mountains, stay calm in the face of darkness, loneliness, and the unknown. It will greatly increase your chances of survival. Many people think that preparing necessary equipment and knowing how to use it are very important, but actually eighty percent of mountain survivals is your reaction(反应) to fear.
Find a hiding place.
Unnecessary efforts will make you sweat and make you cold. Find a hiding place around you before trying to start your own construction. If you are in a snow-covered area, you may be able to dig a cave in deep snow for protection from the wind. You should try to hide yourself in the middle of the mountain if possible. Stay out of valleys—cold air falls, and the valley floor can be the coldest area on the mountain.
Signal rescuers for help.
The best time to signal rescuers(救援者) is during the day. Signal for help from the highest point possible—it will be easier for rescuers to see you, and any sound you make will farther. If you take a box of matches and a space blanket (a special blanket for traveling), build three smoky fires and put your blanket—gold side facing out—on the ground.
Do not walk away.
It will make finding you more difficult, as search teams will be trying to follow your path and may miss you if you have gone off in a different direction. Searchers often end up finding a car with no one.
If you get frostbite（冻伤）, do not rewarm the affected area until you’re out of danger. You can walk on frostbitten feet, but once you warm the area and can feel the pain, you will not want to walk anywhere. Try to protect the frostbitten area and keep it dry until you are rescued.
【小题1】When lost in the mountains, you can increase your chances of survival if you _____.