单项选择题
The number of such vehicles（）steadily increasing.
A.have been B.had been C.having been D.has been
单项选择题 The casual attitude in the US does not mean（）no hierarchy in US companies.
单项选择题 Religion, politics or ethnic background should be touched on（）.
单项选择题 The negotiation will（）in a well-prepared, calm and pragmatic manner, all laced（）a substantial dose of humor.
