题目

在关于x的方程（≠0）中，若与异号，则方程（       ） A． 有两个不等实根       B．有两个相等实根      C．没有实根       D．无法确定 答案：A 七选五阅读题根据短文内容，从短文后的选项中选出能填入空白处的最佳选项。选项中的两项为多余选项。How to keep healthy? It’s easy for us to catch a cold in winter and spring because the weather changes a lot in spring and it is too cold in winter. But if we take care in our life, all of us can keep healthy without any cold.【1】 . This will stop germs（细菌,病毒） passing from one person to another. When you finish your work or before you eat, you’d better wash your hands.【2】 . Use a tissue（纸巾）, and then throw it into dustbins at once. When others around you are coughing, I advise you to turn your head away from the people so that their viruses won’t reach you.Get more fresh air. Germs like staying around in dry and warm rooms. 【3】 . Don’t stay too long in the places with too many people.If flu is going round house or school, you should try to stay away from those who are ill. 【4】Boil your toothbrush for about a minute. This kills germs . 【5】 . If you have used the toothbrush for three months or so, throw it away and buy a new one.A. Have a shower everydayB. Wash your hands oftenC. Don’t use your hands when coughingD. Don’t go out often when you are coughingE. Besides, don’t use the same toothbrush too longF. In this way, you won’t be infected by these peopleG. So you’d better stay in the places with more fresh air