我并不特别喜欢跑步，但为了保持健康，我还是咬牙坚持。

I don't particularly enjoy running, but I ___grit ___my ___teeth and do it in order to keep fit.

面对截止日期带来的巨大压力，她只是咬紧牙关，通宵工作。

Facing the immense pressure of the deadline, she simply ___gritted ___her ___teeth and worked through the night.

这门课程极具挑战性，但他下定决心咬牙坚持到底。

The course was extremely challenging, but he ___gritted ___his ___teeth, determined to see it through to the end.