“大象会在天上飞”是可能的。（判断对错）

小船在静水中速度为v，今小船要渡过一条河流，渡河时小船垂直对岸划行.若小船划行至河中间时，河水流速忽然增大，则(        )

    Here are some tips about how to keep healthy.

1) Healthy food is important. If you want to keep healthy, eat lots of fruit and vegetables. Don't eat much meat.

2) Water is important. Drink water every day. Milk is good for you, too. Don't drink sweet drinks.

3) Exercise is important. You can ride your bike or play soccer. Going swimming is a good idea.

4) Clean air is important. If you are free, you can go to the park and enjoy clean air.

5) Your teeth are important. You should brush your teeth twice a day.

6) Sleep is important, too. Go to bed early. Don't stay up late, or you will feel sleepy.