Does his teacher often help him ______ his study?[ ]
A. at
B. on
C. in
D. with
答案:D
常用水暖管道的填料有()。
A、玻璃纤维
B、聚四氟乙烯生料带
C、石棉盘根
D、耐油橡胶
社会保险费用完全靠代际之间收入转移的筹资模式是( )。
A.现收现付式
B.完全基金式
C.部分基金式
D.个人账户式