--- Beautiful day, isn’t it? Shall we go

已知不等式x²-2x-3＜0的解集为A，不等式x²+4x-5＜0的解集为B．

（1）求A∪B．

（2）若不等式x²+ax+b＜0的解集是A∪B，求ax²+x+b＜0的解集．

如图所示的电路中,电源电压保持不变,小灯泡L上标有“6V 3W”,闭合开关S，将滑动变阻器的滑片P置于中点c时，灯泡L恰好正常发光，当滑片P置于最左端a时，电流表的示数是0.3A，则滑动变阻器的最大阻值是_______Ω。电源电压是_______V。（不考虑温度对灯丝电阻的影响。）

根据汉语提示填写单词。

1. His father's coming back ___________(使得) him feel very happy.

2. Today I came to school ___________(没有) breakfast.

3. I was too busy and ___________(错过) the film "Titanic".

4. I will tell you when he __________(到达) my home.

5. Is the license in one of your __________(衣服口袋) ?

6. --What's wrong? --I ___________(割) one of my fingers just now.

7. If someone ___________(推) hard, the old man will fall over.

8. There are so many ___________(参观者) in the West Lake.

9. You must keep __________(安静) in class.

10. He __________(改变) his name when he was in the USA.

Our car broke down suddenly and the heavy rain        our helplessness.

A．made out

B．led to

C．turned out

D．added to

下列表述涉及的风险有（）种。

①甲公司新推出的产品未取得预期销售业绩

②乙公司电子类产品达到使用寿命后形成难以处理的电子垃圾

③丙公司海上石油钻井平台发生泄漏事故

④丁公司发现做假账的舞弊行为

⑤戊公司被长期雇用的快递公司将重要凭证文件寄丢

A.5

B.4

C.3

D.2