It was raining hard and there was only one________ in the shop at that time. A. passenger B. audience C. customer
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.