问题
选择题
维生素A对人的视力有非常重要的作用，其结构简式如图，下列关于该化合物的说法正确的是
①维生素A是一种不饱和的一元醇；②维生素A含有苯环结构；③维生素A含有两种官能团；④维生素A的一个分子中含有3个碳碳双键。
A．②④
B．①③
C．③④
D．全部正确
答案
答案：B
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维生素A对人的视力有非常重要的作用，其结构简式如图，下列关于该化合物的说法正确的是
①维生素A是一种不饱和的一元醇；②维生素A含有苯环结构；③维生素A含有两种官能团；④维生素A的一个分子中含有3个碳碳双键。
A．②④
B．①③
C．③④
D．全部正确
答案：B
| Read and choose. 完形填空。 |
| Li Ming l to the library three 2 a week, from Monday to 3 . 4 school, he walks home. He does his homework. 5 6:30 in the evening, he eats 6 . After supper, he washes his hands and brushes his 7 . Then he puts 8 his clothes 9 goes to the library. He is a good boy. He works very 10 . |
( ) 1. A. go | B. goes B. time's B. Wednesday B. After B. To B. lunch B. teeth B. in B. but B. hard | C. went C. times C. Thursday C. At C. In C. supper C. face C. too C. and C. good |
