题干

下图是生长素浓度与其作用示意图,相关的表述不正确的是:

A:若处于顶端优势的顶芽处生长素浓度是B点,则该植株侧芽处生长素浓度可以是D点

B:在FC的范围内都能促进生长

C:胚芽鞘的向光弯曲生长也可以用该图来解释,背光一侧生长素浓度如果是E点,向光一侧生长素浓度可以是F点

D:在太空中(重力为0),生长素浓度越高,对植物生长促进越强

上一题 下一题 0.0难度 选择题 更新时间:2017-09-13 06:25:30

答案(点此获取答案解析)

D

同类题4

阅读下面短文,掌握其大意,然后从36—55各题所给的四个选项(A、B、C和D)中,选出最佳选项,并在答题卡上将该项涂黑。

    Every day, I drive home along Colorado Blvd, a wide street with four lanes on each side of the median (中央分隔带护栏). I always notice a homeless man standing on the corner of Colorado Blvd, 1 for spare change with a sign in his hand.
Last Monday, when I was 2 him, he suddenly threw down his sign and rushed into the middle of the street. At this time I 3 a car moving across the 3 lanes of traffic and heading for the  median. The 4 man ran to the side of the car and attempted to push the car back in the right 5. He also knocked on the window of the vehicle, but all  6 Immediately, he ran across the small median into four lanes of oncoming traffic, 7 madly for the cars to stop. Thankfully, all speeding cars 8 to stop just in time to 9 hitting him. The car which was out of 10 came Moving across the median and the four lanes of traffic, where just seconds ago cars had been traveling with 11 speeds.
    The homeless man jumped back in front of the 12 to attempt slowing it down again. By this time, we were able to 13 and help the man stop the car 14 it ran into a supermarket on the other side of the road. As it 15 out, the woman driver had a heart attack while driving and became 16 in the front seat.
    The homeless man is indeed a hero. He spends every day getting 17 by people who are trying not to make 18 contact with him so that they don't feel bad not giving him money. Yet he didn't  even hesitate to risk his life to save this lady and other drivers who would have 19 into her. He didn't think of his safety, nor did he expect anything in return. Heroes do exist in the most 20 places.