How great your idea ____ (sound)!I love it.是不是填sounds?

题目

How great your idea ____ (sound)!I love it.是不是填sounds?
Susan,___(not be) careless when crossing the road.是不是填isn't?
Not only the twins but also their friend __ (plan)a trip to Shanghai at this moment.是不是填are planning?

答案

1 对,是：sounds
2 don't be ( 祈使句否定句是助动词don't +动词原形）
3 is planning ( their friend 是单数,not only ...but also ...是就近原则）