The citizens in Shanghai _______________ the highest building, Shanghai Tower, in the near future.

When summer __, some children will go to the seaside for fun.

The man in a black suit _______ be our youth worker.— I’m sure it _______ be him. I saw him in the laboratory building some minutes ago.

The socks are cheap（便宜的）， I’ll________ it.

The question is too hard to understand. —Why _______ ask the teacher? [ ]