特种作业人员必须按国家规定培训合格，取得（）方可上岗。
A、安全任职资格证书
B、操作资格证书
C、居民身份证
参考答案：B
This building is ___ that one.
A．three metres higher than
B．higher three metres than
C．so high as
D．twice high as
依靠抗体的免疫是（）
A.非特异性免疫
B.细胞免疫
C.特强免疫
D.体液免疫
