我国陶器制作的鼎盛时期,应该在[ ]
A.北京人时代
B.山顶洞人时代
C.半坡、河姆渡时代
D.大禹时代
答案:C
下列关于补体生物学活性的描述,错误的是()
A.细胞毒作用
B.调理作用
C.免疫黏附作用
D.中和病毒作用
E.抗过敏作用
He was in hospital for six months. He felt as if he were ______ from the outside world.[ ]
A. cut down
B. cut off
C. cut in
D. cut through