佝偻病的主要病因是
A.缺磷
B.缺钙
C.缺VitaD
D.缺锌
E.缺VitaA
参考答案:C
根据所给图片,补充句子。
1. The sign says, " ."
2. My sister every day.
3. He very much.
4. Li Ming yesterday evening.
5. They are in .
能开挖停机面以上土方的单斗挖土机有()。
A.正铲挖土机
B.反铲挖土机
C.拉铲挖土机
D.抓铲挖土机