砂浆的搅拌时间每盘不应少于（）分钟。
A.1
B.2
C.3
D.4
参考答案：B
血淋与尿血的最主要鉴别在于
A．小便血色的鲜红还是紫暗B．小便量的多少C．小便有无混浊D．小便是否畅通E．小便时有无疼痛
Why not ________ an English club to practice ________ English? [ ]
A. join; speaking
B. to join; speaking
C. join; to speak
D. to join; to speak
