题目

据科学分析，海洋生物比陆生生物进化的速度慢，下列解释其原因不正确的是（ ） A．海洋生物一般比陆生生物低等 B．海洋比陆地环境相对稳定，生存斗争进行比较缓和 C．海洋生物比陆生生物高等，不需要生物进化 D．海洋中弱肉强食，很多物种还未进化到高水平就被淘汰了 答案：ACD 解析: 生物进化的速度取决于环境的变化程度，环境变化越大，生存斗争越剧烈 ，生物进化的速度就快。海洋比陆地环境相对稳定，所以相对来说，海洋生物比陆生生物进化的速度慢。进化的趋势是水生到陆生，并不是说所有海洋生物要比陆生生物低等。短文选词填空。 terrified   face  studying  regard   decide Tom has changed a lot．He used to be shy ,but now he is outgoing ．He used to make a lot of trouble．He always wasted his time in the  past．He didn't used to         (1) his problems．He always made some mistakes．He used to be afraid of the dark, but now he is            (2) of being alone．He slowly realizes that he needs to spend more time             (3)．So he made a         (4) to study hard this term．He thinks it's his duty to study．Now he can deal with his problems．He        (5) his problems as challenges．