呼吸阀放置不得倾斜或倒置，以防（）。
A.呼吸阀从罐顶滚落
B.呼吸阀内机油流出
C.损伤呼吸阀
D.呼吸阀自动关闭
参考答案：A
Read and write.
1. (Her She) hair is long and brown. (Her She) is pretty.
2. Your eyes are _ (big bigger), but my eyes are _____ (big bigger) than yours.
3. Miss Liu _ (has is) a small nose. But her mouth (is has) big.
4. Amy is 2 years Chen Jie. (old)
5. Sarah is 3 kg John. ( heavy)
6. Miss Zhang is 160 cm. I am 150cm. I am than Miss Zhang.
7. Miss Li is 25. Mr Ma is 30. Miss Li is Mr Ma.
按照成鹅体重分，（）公斤以上为中型鹅。
A、3-5
B、5-7
C、8-9
