要提高岩心收获率，必须对取心的技术措施、操作技能、取心工具等方面进行深入的分析研究，逐步提高取心钻井的工艺技术水平。
参考答案：对
With his blows knitted, the doctor contemplated the difficult operation he had to perform.
A．succeeded in
B．decided against
C．went on with
D．thought deeply about
开清棉机械联动的控制方法有（）、（）和（）。
