根据短文理解，从A、B、C、D四个选项中选择最佳答案填空。

    Can you imagine astronauts' everyday life in space? They also need to eat,  1 , exercise and relax. They do the same things as us, but they do2 differently.

    On Earth, we put food on a plate and water in a glass. Gravity(重力) holds the food down and keeps the water in the glass.  3 there is almost no gravity in space, so food can float(漂浮) away, and astronauts must eat and drink4  .

    Sleeping is very different in space. Some astronauts like to float in the air, but most like to be in a 5bag. They tie the bag to a wall 6 they won't float away at night. Exercise is very important in space. On Earth, your legs 7 your body, but in space, astronauts float. So they do not use their legs often. This is very  8their legs, so they must exercise for thirty minutes every day.

    After a day's work, astronauts relax. They may listen to music, read, watch films, play games, or talk to their friends and families  9  the radio. Sometimes they just enjoy 10 in the air.

福州乌山的琵琶亭有一幅对联，上联是：一弹流水一弹月。下面最适合作为下联的一句是(    )

下列说法：
①命题“存在$x\in R,2^x\le 0$” 的否定是“对任意的$x\in R,2^x>0$”；
②关于x的不等式$a<{\sin }^{2}x+\frac{2}{{\sin }^{2}x}$恒成立，则a的取值范围是a<3；
③函数$f\left(x\right)=a{\log }_2\left|x\right|+x+b$为奇函数的充要条件是a+b=0；

其中正确的个数是（   ）

“人人有贵于己者，弗思耳矣。”（每个人皆有他自己的尊贵之处，只是不去思考罢了）只要养成思考的习惯，生活的质量自然会随之提高，生命的内涵也将更为丰富。哲学是我们品味人生的开始。这从哲学上启示我们要（    ）