平缝也称()、(),是机缝中最基本,最使用最广泛的一种缝法。
参考答案:合缝;平接缝
用所给词的适当形式填空。
1. Half the boys in my class ______ (like) playing basketball.
2. The mother asked his son ______ (not ride) too quickly on the way to school. It's dangerous.
3. If you exercise every day, you ______ (be) healthy.
4. What will happen if Lucy ______ (bring) her friends from other school to the party?
5. He is a difficult man ______ (communicate) with.
毕脱斑的形成是因为()。
A.维生素A摄入过量
B.核黄素缺乏
C.体内脂质过多
D.硫胺素缺乏
E.维生素A摄入不足