题干

18O标记的H2O浇灌植物,在光照充足的条件下,植物体内及周围空气中存在18O同位素的物质及其相应生理过程的叙述中,不正确的是(     )

A:植物周围的氧气中——光合作用的光反应

B:植物二氧化碳中——有氧呼吸的第二阶段

C:植物周围的水蒸气中——植物的蒸腾作用

D:植物体内的有机物中——利用外界二氧化碳进行光合作用暗反应

上一题 下一题 0.0难度 选择题 更新时间:2015-01-13 09:13:06

答案(点此获取答案解析)

D

同类题5

先读通下面的短文,然后从各题所给的A、B、C、D四个选项中,故答案选出最佳选项。

    It has been some time since(自从) Jack saw the old man. In fact, Jack moved away from the country and was busy 1his work. There, Jack had2 time to think about the past and often had no time to 3 with his wife and son. He was working for his future.

    One day, his mother 4him over the phone that Mr Belser, their neighbour had died and the funeral(葬礼) would be 5Wednesday.It took a long time 6 Jack gave an answer because he had not thought of Mr Belser for a long time. “Well, he didn't 7 you. Every time I saw him, he'd ask 8you were going. He'd 9the days you spent with him, ” Mum told him.

    It had been about two weeks since Mr Belser died. One day, Jack 10 a package(包裹). There, inside was a gold 11.The box was from Mr Belser. Jack's hands shook(晃动) as he read the note inside. “Upon my death(死亡) please give this box to Jack Bennett. It is the thing I value most( 珍视) in my life.” There inside he 12 a beautiful gold packet watch. He opened the cover. Inside he found these words, “Jack, thanks for your 13 !——Harold Belser.”Jack held the watch for a few 14, then called his office and canceled (取消) his meetings for the next two weeks. He needed some time to spend with his wife and son.

    No matter how( 无论怎么样) busy we are, we should always remember to spend some time with the person we love. They are 15part of our life.