问题
单项选择题
螺杆钻具入井前应检查（）是否灵活。
A、旁通阀
B、旁通阀活塞
C、芯轴转动
D、旁通阀活塞和芯轴转动
答案
参考答案：D
搜题请搜索小程序“爱下问搜题”
螺杆钻具入井前应检查（）是否灵活。
A、旁通阀
B、旁通阀活塞
C、芯轴转动
D、旁通阀活塞和芯轴转动
参考答案：D
| 以方框中选出恰当的句子补全对话。 | |
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