叶脉是植物叶片输导组织在叶片表面形成的网络。( )
参考答案：对
根据要求改写句子。
1. I often have lunch at school. (主语改为第三人称单数he)
_____ often _____ lunch at school.
2. Carol likes skating. (改为否定句)
Carol _____ _____ skating.
3. These socks are only ￥5. (对画线部分提问)
_____ _____ are these socks?
4. Can I help you? (改为同义句)
_____ can I do _____ you?
5. Thank you. (写出答语)
_____ _____.
哮喘可分为三期（）。
A.急性发作期（acute exacerbation）
B.慢性持续期（chronic persistent）
C.临床缓解期（clinical remission）
D.以上都对
