Taking a boat must be a lot more fun than taking a bus.同义句Taking a boat ( )be a lot more fun than taking a bus.

问题描述:

Taking a boat must be a lot more fun than taking a bus.同义句
Taking a boat ( )be a lot more fun than taking a bus.

can't ,因为must作猜测时改否定应该用can't

填can't
must be 是“一定会”的意思,否定式是can't be,“不可能”的意思.