下列说法正确的组合是( )①病毒是生命系统结构层次中最小单位②德国的魏尔肖对施莱登和施旺的细胞学说的补充内容是:新细胞可以从老细胞中产生③具有生命的结构都有蛋白质和核酸④只能自己合成,不能从食物获取的氨基酸叫做必需氨基酸⑤还原性糖和DNA的鉴定试验,都需要在沸水中水浴加热处理⑥观察花生子叶中脂肪颗粒实验和观察根尖有丝分裂实验,都用到酒精,其作用是不一样的
A:①②⑤
B:②③⑤
C:②③⑤⑥
D:③⑤
读课文《穷人》,说说下列句子中省略号的作用。
我自作自受……嗯,揍我一顿也好!
依次填入下面一段文字横线处的语句,衔接最恰当的一组是( )
柳宗元与山水的相遇,多少有些偶然、被动和无奈。 。 。 , , 。 。最后,山水与人合而为一,并且化为山水之文。
①与此相应,山水也走进了他的文章之中
②不过,或许是永州山水的深情召唤
③他不是自愿来到这里,而是被无可抗拒的力量抛掷到了这里
④或许是自己的突然醒悟
⑤当他来到这块荒蛮瘴疠的土地时,心情的消沉郁闷可想而知
⑥总之,柳宗元终于在山水中找到了自己新的生存天地
根据短文理解,选择正确答案。
There are fifty students in our class. There are twenty-four boys and twenty-six girls. Some students live near the school, and some others live far from school. About half of the students usually come to school by bike. They often get to school at a quarter to seven. About fifteen students often come to school by bus. They often get to school very early, too. Another ten students come to school on foot. Their homes are near the school, but they are often late for school, because they get up late.
早春呈水部张十八员外 韩愈
天街小雨润如酥,草色遥看近却无。最是一年春好处,绝胜烟柳满皇都。