We’ll have a hiking trip, but when shall we meet? —Let’s make it ______ half past eight ______ the morning of June 21. [ ]

My brother likes math ________ chemistry. [ ]

The car accident happened ____ a cold winter morning. Luckily, no one was hurt.

Must I clean the classroom now, Miss Wang?–No, you needn’t . It by Bill.

It is too noisy. I can hear what Mr. Wang is saying.