人员密集场所房门至外部出口或封闭楼梯间、防烟楼梯间的最大允许距离一般控制在()之间。(中)
A、15~20m
B、20~30m
C、30~40m
D、15~40m
参考答案:D
普通股票的基本特征为,普通股票是()
A.最基本最重要的股票
B.标准的股票
C.收益最高的股票
D.风险最打的股票
Grover Cleveland was the first president ______ in the White House.
A.got married
B.to get married
C.has got married
D.was married