硅酸盐水泥初凝时间不得早于45min，终凝时间不得迟于（）min。
A．300
B．390
C．600
D．690
参考答案：B
尿培养标本应该采集（）
A.晨尿
B.随机尿
C.餐后尿
D.清洁中段尿
E.消毒尿
—We want someone to design the new art museum for us.
—______ the young fellow have a try?
A．Shall
B．May
C．Will
D．Need
