Instead of just letting themselves drift off into dreamland, they kept on checking to see if they were still awake, and that quick mental check woke them up.

他们无法让自己沉入梦乡，反而不断自省是否尚未入眠，而正是这种时时短促的心理检查令他们难以入眠。

youdao

A slang term for an internal drift diameter gauge typically used to check casing or tubing joints before they are picked up and run into the wellbore.

在套管单根或油管单根被提起和下入井筒以前对其进行检查所用的内通径规的习用语。

youdao

The assumption that any alien signal would exhibit a Doppler drift has also been incorporated into all subsequent SETI projects, which invariably check for signals at drifting frequencies.

来自外星文明的信号将发生多普勒漂移的假设也被采纳到后来所有的SETI项目中，这些项目都无一例外的检查信号的频率漂移。

youdao