A study shows that the agent hasn’t broken rules， but ________ responsibly.

It’s a pity that I can only live here for two days __________.—Why not stay for another day I know you have three days off.

当你向别人打招呼时,你不可以说“_______”.

There is little milk in the fridge, ________

He was so absorbed in his work that not a sound ______.