商周时期手工业繁荣具体表现在
①青铜铸造②陶瓷业③冶铁业④玉器制造业[ ]
A.①②③
B.②③④
C.①②④
D.①③④
答案:C
— What did the doctor say?
— His advice was that you ______ do more exercise. [ ]
A. had to
B. would
C. should
D. needed to
日本血吸虫卵能进入肠腔随粪便排出体外的原因有().
A.肠蠕动增强
B.腹内压增高
C.血管内压增加
D.卵内毛蚴分泌物破坏肠壁
E.肠道细菌协同作用