题目

下列说法中错误的是 A．H3PO4的摩尔质量是98 g B．1 L 1 mol·L－1的MgCl2溶液中，Cl－的浓度为2 mol·L－1 C．若NA表示阿伏加德罗常数的值，则标准状况下11.2 L N2所含N原子数为NA D．从3 mol·L－1的Na2SO4溶液中倒出5 mL溶液，Na＋的浓度为6 mol·L－1 答案：A 解析:摩尔质量的单位是g·mol－1，A项中单位错误Spring is a good season to fly kites. You can fly your kites in the park, in the field or on the play ground. There are many different kinds of kites. Some look like birds; Some look like planes and some look like butterflies. People often fly kites on a sunny and windy day. And the best month for flying kites is March. How can we fly our kites in the sky. First, we run with our kites against the wind. Then when the kite can fly in the sky, you can just stay there with your string reel(线轴) in your hand. When the kite doesn’t fly in the sky, just adjust(调整) the string reel. The string on the reel must be very strong. If you want to fly kites very well, you should practice it more with your friends. Maybe you feel a little difficult at first, but if you fly kites often you will find it very easy and interesting. Flying kites is a very good activity in spring, and a lot of people like it.【小题1】Where can’t you fly your kites?A．In the park.B．In the field.C．In the street.D．On the playground.【小题2】When do people often fly kites?A．On a cold day.B．On a rainy day.C．On a cloudy day.D．On a sunny and windy day.【小题3】If the kite can’t fly well in the sky, what should we do?A．Run quickly. B．Adjust the string reelC．Run against the wind.D．Stay where you are.【小题4】What does the underlined word “against” mean?A．反抗B．碰撞C．逆着D．对立【小题5】Flying kites is a good sports in         .A．springB．summerC．autumnD．winter