题干

下列对组成细胞分子的描述,正确的有(  )

①核酸、酶、果糖、脂肪均含有元素C、H、0、N 

②所有的酶都是蛋白质  

③对蛋白质的检测可用斐林试剂,颜色呈红黄色  

④人体内参与信息传递的分子都是蛋白质   

⑤生物膜上的载体都是蛋白质  

⑥蛋白质的多样性与氨基酸的种类、数目、排序等有关

A:一项

B:两项

C:三项

D:五项

上一题 下一题 0.0难度 选择题 更新时间:2019-11-29 12:13:54

答案(点此获取答案解析)

B

同类题4

书面表达

假如你是某英语杂志社编辑王林,根据下面中学生小明的来信,给他写一封回信,解答他的困惑。

要求:1. 观点鲜明,结构合理,内容连贯;

2. 词数80左右,信的开头和落款已给出,不计入总词数。

Dear editor,

   Nowadays, many junior high school students are completely getting relaxed from busy study after graduation,  so what they would like to do most is to throw books away, hang out with friends at daytime and stay up late at night playing computer games or watching TV. What's your opinion about this? I'm looking forward to your reply.

                                                                                                                                                                                                      Yours sincerely

         Xiaoming

Dear Xiaoming,

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Yours,

Wang Lin