As he works in a remote area, he visits his parents only _______ .

The repair work may take us a long time，but          it’s worth trying.

    Dream of the Red Chamber is ________worth ________because we can learn a    lot about the noble families in the feudal society.

We don’t have enough money .We,_______, can’t afford to buy the car.

He likes sports, ________ I’d rather play games on computers.

He talks as if he knew the truth. _______, he knows nothing about it.

．After many trials and failures, the farmer＿＿built a homemade plane that successfully got off the ground.

—Why is Thomas so lonely every day?
—Because he has        no communication with others.

We used to see each other       , but I haven’t head from him since last year.

----What a mess! You need to clean the classroom ________ after school!
----But the final exam is approaching!