The number of students in our school ________ 2000 and a number of them ________ good at playing basketball.

下列各句中，没有语病的一句是（ ）

We should mind our behaviour ______ public

We’ll have a picnic in the park this Sunday _____ it rains or it’s very cold

I wish I at my sister’s wedding last Tuesday, but I was on a business trip in New York then.