fast runner Su Bingtian is! He finished______ in the 100- metre race in 9．99 seconds．

c. Whata D. How a

I hope you don’t mind my opening thewindow.— _____ . It’s much too hot here.

It is important to ________ the latest research. [ ]

The Education Department says that school safety has set off alarm bells with frequent reports of serious accidents______ students got injured or killed.[ ]