I don’t know _____ he will come tomorrow, ______he comes, I’ll tell you.A.if…whetherB. whether…whetherC. whether..if
David ________ chicken, but he ______ fruit.
Is this your pen? Please call me _____ 0833-8817171.
This is ____ interesting book, please ___ it _____ here.
Let’s ________ now.
---What’s this______ English? ---______ a ruler.