题干

下列关于植物生长素生理作用的叙述中,正确的是(    )

A:顶芽生长占优势时侧芽生长素的合成受到抑制

B:燕麦胚芽鞘中生长素的极性运输与光照方向无关

C:草莓果实的自然生长过程与生长素无关而与乙烯有关

D:温特的实验中生长素从胚芽鞘尖端基部进入琼脂块的方式是主动运输

上一题 下一题 0.0难度 选择题 更新时间:2014-04-21 05:57:58

答案(点此获取答案解析)

B

同类题2

阅读下面短文,从A、B、C、D四个选项中选出最佳选项。

    The government in China ended his one-child policy and let families have two children instead in 2015.

    A Chinese Communist Party statement gave a number of reasons for the change in policy. The statement said the change is meant to balance population development, stop a falling birth rate(出生率)and strengthen the country's labor force(劳动力). China, with the largest population in the world, started the one-child policy in 1980. But the government allowed only a small number of couples to have two children. For example, some families in the countryside could have two children, if the first-born is a girl.

    In 2013, the Chinese government gave other couples a chance to have two children if one of them was an only child.

Jiang Quanbao, a teacher and population expert, explained how Chinese families react(反应) to the newest policy. "Too many young people in the cities are no longer interested in having a second child," he said. "People in the countryside are more interested. But some of them are already allowed to have two children." At the end of 2014, China had a population of 1.37 billion people. A total of 800 million of them have jobs. But the labor market need of labor by the year 2050. With the two-child policy, an increase in births can solve this problem.

    Boys and girls, what do you think of the two-child policy? Do you want to have a new-born brother or sister?