与食管癌发生无关的因素是()
A.食用过热饮食
B.食物中含较多亚硝胺
C.反流性食管炎
D.食管痉挛
E.缺少微量元素
参考答案:D
用所给词的适当形式填空。
1. The teacher told us not to go ( swim) alone in the river.
2. The Women's World Cup _ (not begin) until 1991 when China hosted it in Guangzhou.
3. Jackie Chan is a famous) _ (act).
请简要说明以“事”立小卷方法的优点。