题干

植物的光合作用受各种因素影响(如图所示)。下列相关叙述中正确的一组是(   )

①若适当提高温度,则Y点应右移
②若此图示该植物在20oC时的关系图,如将温度提高到  30oC(其他条件表不变),则X点应上移 
③若曲线表示阴生植物,则Y点应左移
④若曲线表示阴生植物,则Z点应右移

A:①④

B:②④

C:②③

D:①③

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答案(点此获取答案解析)

D

同类题2

Fill in the blanks according to the passage .Only one word for each blank.

    Once upon a time, there was a millionaire who loved money more than the other things in the world. He didn't know exactly how much he had, so he took on a little girl to count all his money for him.

    It took the little girl six days to count all the money. When she told the millionaire that he had forty-two million dollars, he was wild with joy and asked, “How much money do you want?” He thought she was only a child and he could give her less money.

    The girl said, “Well, I worked for six days, so I think you should pay me for six days. Give me two pennies for the first day. Each day after that, just give me the amount you give me the day before, multiplied(乘) by itself.”

    The millionaire thought that in this way he would only have to give her a few dollars. What a foolish girl!

    On the first day the millionaire paid her two pennies, and on the second day, two pennies times two pennies, or four pennies.

    Each day after that, he gave her the number of pennies he had given her the day before, multiplied by itself. And by the sixth day the foolish millionaire had to give the clever girl all his money.

    Long long ago, a millionaire loved money than anything ____ in the world. One day he took on a girl to count his money. The girl spent six days in ____ his money. The millionaire asked the girl how much money he should ____ for what she did. The girl answered he should give her the amount he gave her the day before, multiplied by itself.

    The millionaire ____ with the girl. He thought the girl was a ____. In fact, the girl was so clever. The millionaire had to give the clever girl all his money.