_________has already been pointed out, grammar is not a set of dead rules.

Joe has been studying Chinese for three months．but he can ________ understand people when they speak Chinese．

I’ve tried very hard to improve my English. But by no means _______with my progress.

Thousands of years ago people discovered the phenomenon by chance, and this was _____ the idea of the compass first came from

My son is always full of and hardly feels tired.