They … . A.should be warn B.should had warn C.should have been warned Answer and Feedback Answer:C do you want? view more test Xem thêm Share this post Some other questions you may be interested in. I knew ………………………. I had made a mistake. ……………………….. we heard the noise, we ran out of the house. He worked hard ………………………….. he could earn enough to make a living. …………………………. I get a day off, I will visit my parents. He died in the town ………………………….. he was born. ………………………….. the soldiers were poorly armed, they offered a stubborn resistance. He spends more ………………………….. he earns. …………………………. you mend your ways, you will land in trouble. ………………………… you work conscientiously, you will achieve success. The washing machine ………………………… I bought yesterday is energy efficient.