_________, I think, and the problems would be settled.

A．If you double your efforts

B．Making more efforts

C．So long as you don’t lose heart

D．A bit more effort

测井仪器在套管鞋处遇卡时，应立即（）。

A.上提电缆拉力至电缆最大安全拉力值

B.上提电缆拉力至仪器串弱点张力值

C.停车后再采取相应措施

D.拉断电缆