It _________ be the only way to solve the problem. There are other choices.
may not
mustn’t
need
should
The girl is too young to look after __________. You shouldn’t leave her at home _________.
Do you know the girl _________a red dress?
Alice found a key __________the door on a small table.
The rabbit jumped ________a big hole. Alice didn’t want to let it get _________
——You look excited. What happened?——I saw a rabbit and ran _________ the field after it.