我太累了，脑子都转不过来了。

I was so exhausted that I ___could ___not ___think ___straight.

在工作上承受巨大压力时，她发现自己根本无法清晰地思考。

Under immense pressure at work, she finds she simply ___cannot ___think ___straight.

熬了一夜之后，你别指望他能理清思绪。

After a sleepless night, you can hardly expect him to ___think ___straight.