操作管柱式常规测试管柱的特点()。
A.测试阀主要是MFE和HST
B.测试管柱操作复杂,可靠性差
C.不能用于小斜度井
D.适用于高产层测试,但不能用于低产层测试
参考答案:A
易导致癌变的胃炎是()
A.肥厚性胃炎
B.胃窦胃炎
C.胃体胃炎
D.萎缩性胃炎
E.浅表性胃炎
— Could you tell me how the sea sand comes about?
— Sea waves dash against the rock. In this way, the sea sand ___. [ ]
A. comes into use
B. comes into office
C. comes into effect
D. comes into being