【推荐1】________ we know the importance of saving water, we should take actions as quickly as possible.

A．Since

B．Until

C．Before

D．Although

【推荐2】—I hear that you have lived in Yangzhou since you got married.
—That’s true. ________ the cost of living in Yangzhou is among the lowest in Jiangsu Province, people live there comfortably and happily.

A．Since

B．When

C．Although

D．Unless

【推荐3】I don’t have to introduce her to you ________ you know the girl.

A．until

B．unless

C．since

D．but

【推荐1】—Excuse me, Jim, what’s the meaning of “Use it or lose it.”?
—It means even if we learn something well, we will forget it ________ we use it.

A．while

B．until

C．unless

【推荐2】________ troubles me is ________ I should go with you.

A．What; whether

B．What; what

C．Whether; that

D．That; whether

【推荐3】These responsible workers won’t go back home______ they finish their project.

A．when

B．if

C．until

D．but