问题 单项选择题

下列对挥发油通性的叙述,错误的是

A.大多具有特殊而浓烈的气味

B.易溶于有机溶剂

C.具有挥发性

D.性质稳定,与空气经常接触不易变质

E.有些挥发油可在低温下析出固体

答案

参考答案:D

解析:常温下挥发油大多为五色或淡黄色的透明液体,多具浓烈的特异性嗅味,常温下可自然挥发,不溶于水,而易溶于各种有机溶剂,与空气及光线经常接触会逐渐氧化变质,冷却条件下挥发油主要成分常可析出结晶,称“析脑”。

完形填空

success, luck, friend, none, to, number, look, failure, other, if, nobody, into

What’s the most important thing for you to have in your life? Somebody mentions hardwork,      小题1: suggest knowledge, love and luck. If you arrange (排列) the 26 English letters in order and use  小题2:   to represent each of them, for example, 1 for a, 2 for b, 3 for c… 26 for z, you can change an English word   小题3:  a number. So hardwork becomes 8+1+18+4+23+15+18+11="98," meaning 98 is its mark. Knowledge:  11+ 14+ 15+ 23+ 12+ 5+ 4 + 7+ 5="96," love: 12+15+22+5="54," and     小题4:   : 12+21+3+11="47," a small mark.  小题5:   of these words can give one a full mark. What about money? It can’t, either.

Then what else? Don’t be worried. You can always find an answer      小题6:   a problem in your life, when you change your way of    小题7:    at things or doing things, or your attitude(态度). Yes, attitude is the word. See for yourself: attitude: 1+20+20+9+20+21+4+5="100," a full mark. Different attitudes lead to different courses of life. Most time people hope for a better life. It is possible that they will have a better life 小题8:  they change their attitudes. When you change your manner and become      小题9:   towards others, you’ll meet more smiling faces towards you. In the same way, if you take a positive attitude towards      小题10:   , you’ll find it’s also rewarding(有益的) though it has caused you losses(损失).

单项选择题