克山病可能是缺哪种元素()
A.缺铁
B.缺硒
C.缺维生素C
D.缺维生素B
E.缺锌
参考答案:B
对于掺用缓凝型外加剂、矿物掺合料或有抗渗性要求的混凝土,覆盖浇水养护的时间不得少于()。
A.7d
B.10d
C.14d
D.15d
290. The little girl ________ of her own face in one of the shop windows and she felt countrified(土里土气) by herself.
A.caught sight
B.caught sigh
C.looked
D.looked into.