钻井液短路循环的原因有哪些?
参考答案:
(1)井下钻具刺坏、倒扣、脱扣、断落等。
(2)地面高压管线(闸门、法兰、油壬及焊口等)刺坏。
(3)闸门倒错,如灌泥浆闸门未关等。
The film star and her film _____ you have just talked about are well known to everyone. [ ]
A. that
B. which
C. who
D. whom
植物转变为泥炭后,下列哪些成分完全消失了?()
A.水分
B.蛋白质
C.纤维素
D.碳水化合物