用所给词的适当形式填空
He ________ (tell) to do it at once.
Mooncakes ________ (make) by his mother every year.
How many magazines can ________ (borrow) from the library every week?
I think it would be ________ (good) to have a TV set than to have a radio.
--- What is the knife used for?
--- It's used for ________ (cut) things.
A chef ________ (call) George Crum invented potato chips.
Personal computers ________ (invent) in 1976.
What ________ electric slippers ________ (use)for?
Edison was a great ________ (invent). He had 1093 ________ (invent) during his lifetime.
What do you think is the most ________ (help) invention?