Welcome to the City Zoo! There are many1in the zoo. Let’s see the koalas first. Koalas are2Australia. They are quiet,3and cute. Children like them very much. The kangaroos (袋鼠) are also from4. They are quiet and interesting,5they are not friendly.
The giraffes come from Africa. They have a6neck (脖子). They like to eat leaves. The lions are also from Africa. They are exciting, but a little7. Many people don’t like8. We also have pandas. They are from China. They are very cute and friendly, but they are very shy. So please be9.
Have10and enjoy yourself here!

测定木块和长木板之间的动摩擦因数时，采用图甲所示的装置（图中长木板水平固定不动）