下列建筑钢材中，( )适用于各种重型结构、高层结构、大跨度结构及桥梁工程。
A．碳素结构钢
B．低合金高强度结构钢
C．高级优质钢
D．优质钢
参考答案：B
The professor, _____ some of his assistants, _____ to attend our discussion this afternoon.
A．and; is
B．as well as; is
C．or; are
D．except for; are
五仁丸是依组成药物味数命名的()
