—This pair of shoes ____ belong to Jack. He likes this kind very much.—It ____ be his. It’s too large for him.
Thank you for giving us some useful advice _______ how to deal _______ the problems.
Things made of plastic are usually _______, but they are _______ to get polluted.
All the club members _______ the floor when they heard someone _______ for help.
A fridge is used to keep food which goes _______ very _______.
—Our P.E. teacher isn’t as young as he _______, is he? —No, but he is one of _______ in our school.