患儿，2岁。发热，体温38℃，鼻塞流涕，咳嗽，皮疹初现，疹色红润，点粒稀疏，躯干为多

已知集合A={x|3≤x＜7}，B={x|2＜x＜10}，C={x|1＜x＜a}，全集为实数集R．

（Ⅰ）求A∪B；

（Ⅱ）如果A∩C≠∅，求a的取值范围．

If you often feel tired and the doctor can’t find anything wrong with you, you may be in a state of subhealth(亚健康). Subhealth is a state between health and illness. Most of the subhealthy people are middle-aged ones who are usually stressed out because of work and family. And some of them are students who are having exams.

If you are subhealthy, it is not difficult for you to become well soon. You should have good living habits. For example, you should get up early and go to bed early. And you should exercise regularly（有规律地）. Exercising can keep you healthy. As for meals, it is better to eat less salt and sugar. Vegetables, fruit and fish are important to your body. You should eat more of them. It is not good to eat too much at one meal, because it may cause unhealthy changes in the digestive tract（消化道）. And at last, a balanced diet is very helpful in staying away from（远离）subhealth.

小题1:How may you feel if you’re subhealthy?

A．Happy

B．Comfortable

C．Tired

D．Sad小题2:According to the passage, who will probably(可能地) be subhealthy?

A．Teachers and students

B．Parents and children

C．Middle-aged people and students

D．The young and the old小题3:What should you do if you are subhealthy?

A．Relax and have good living habits

B．Go to see the doctor and ask for some medicine.

C．Go to hospital in foreign countries.

D．Stay at home and not talk to others小题4:If you want to have good living habits,      .

A．you need to get up early and go to bed early.

B．you should exercise very often

C．you should eat less salt and sugar and eat more vegetables, fruit and fish

D．All above(上边的)小题5:What is the main(主要的) idea of the passage（短文）?

A. What is subhealth.

B. How to keep away from subhealth.

C How to keep subhealthy.

D. Why are you subhealthy?

气球下吊着小球以10m/s的速度从地面匀速上升，4s后小球脱落，求：

（1）小球还要上升多高？

（2）小球脱离握后再经多少时间着地？（g=10m/s²）

关于静止在水平地面上的物体，以下叙述中的两个力属于相互作用力的是（　　）

A．地球对物体的吸引力与物体受到的重力

B．地面对物体的支持力与物体的重力

C．物体对地面的压力与地面对物体的支持力

D．物体对地面的压力与物体的重力

承受重载荷或冲击载荷的零件需采用（）制坯。

A、铸造

B、锻造

C、焊接