题目

阅读下面短文，根据句子结构的语法性和上下文连贯的要求，在空格处填入一个适当单词或使用括号中词语的正确形式填空。Most of us don't pay much attention to the 【1】(important) of eye care. It is said that if you take care of your body, then you can be healthy. That is why our eyes should【2】 (give) a lot of care.There are several causes leading to poor eyesight like lack of food, genes(基因) and aging(老化). Televisions, computers and reading are【3】the causes of having poor eyesight. If you happen to work in front of the computer, i下列有关生长素的叙述，错误的是 [　　] A．运输方式是主动运输 B．色氨酸经过一系列反应可转变成生长素 C．只能从形态学上端运输到形态学下端 D．合成部位是幼嫩的芽