-Mr Li lives______, but he doesn’t feel _____because many volunteers often visit him.
I don’t know _____ or not he will come . _______ he comes , I will call you .
The robot needs _______ once a month. And we will check it for you for free.
We didn’t know how to find them because they didn’t tell us _______.
In order _______ his English,he joined an English club.
Don’t make the students _______ this or that . They are busy.