题干

全球温室效应是由于工业生产排放过多的温室气体造成的.温室气体是指(  )

A:二氧化硫

B:二氧化碳

C:氟利昂

D:二氧化氮

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答案(点此获取答案解析)

B

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完形填空

    I felt like a good mother on that summer morning. I'd 1 up early, made a picnic lunch2 my three- and five-year-old daughters into the car, driven to my friend's house, packed her and her3 into the car, and driven the hour and a half to the shore where we4 our towels on the sands by 10 a.m.

    Soon the girls began running. About 50 yards from us, a man, maybe 5 his late 50s, was fishing. The girls stood next to him and watched with their mouths open 6 he cast the lines. He smiled at them. They all ran back to us except my three-year-old Drew, who7 just seated herself next to the white bucket where the man was 8 planning to put the fish he caught.

    However, suddenly a 9 came to my mind. Is it dangerous for Drew to stay there with the stranger? Good moms should also teach daughters that the world is dangerous. Then, I watched them like there was a hidden 10 in the lifeguard chair filming the man as America's Most Wanted. Every few minutes, I looked to my five-year-old to make sure she hadn't been 11 out to sea, then back to Drew to make sure there was no 12 between her and the stranger.

    When I looked at Drew again, she had started 13 with the man. She was probably telling him where we lived and how her father was away on 14. He nodded. She kept talking. He nodded again, then they laughed.

    A few seconds later, she ran back to us, with a toy fish in her hand. It must have been something 15 he used for bait(饵). The three other girls were 16 so they didn't try to 17 how eager they were to have one.

    Just when I was at a loss, there he was: the man, standing right next to us. He was holding three more toy fish. He handed them to each of the girls. By their 18 I realized that he was 19 a warm-hearted man, meaning no harm at all.

    “Thank you”, I said, realizing that yes, there is evil in this world…but there is also good, and 20 in strangers, and lessons for mothers to learn that only three-year-olds could teach them.