The earth will become worse and worse ________ we do something to stop her from being polluted.

How was your visit to the World Park Did you enjoy there, children—Wonderful! We had great fun.

Do you think it’s a good idea to make friends with your students? — _____, I do I think it’s a great idea [ ]

下列句子中，没有语病的一项是（ ）

Linda doesn’t know __________about her problems.