如果两个相似三角形的面积的比是4：9，那么它们对应边长的比是______．

Most people want to work, but in today’s word ,it is more difficult to find work for everybody.The economics of the world need to grow by 4% each year just to keep the old number of jobs for people.

Often this is not possible,and so more people are out of work.

Some people have no jobs now because new machines can do the work of many people do in a short time.Also, machines do not ask for more money and longer holidays. In all the countries of the world, machines are taking work from people ,not only in factories but also on the farms.

One machine can often do the work of forty people. About 75,000 people are moving to the cities a day to look for jobs ,but only 70% of them can find jobs .

小题1:The economics of the world need to grow to______.

A．get more money

B．keep the old number of jobs of people

C．make new machines

D．let people look for jobs小题2:Some people are out of work because _______.

A．of the machines

B．they are old

C．they ask for more money and longer holidays

D．they want to move to the cities小题3:About machines,which of the following is NOT　RIGHT?________.

A． Machines can do the work of many people do in a short time.

B． Machines do not ask for more money and holidays.

C． Two machines can do the work of eighty people.

D． Machines cant’t take work from people at all.小题4:.How many people can’t find jobs every day _______?

A．75,000

B．52500

C．22500

D．52500小题5:.From the passage, we know _______.

A． it’s not possible for everybody to find work.

B． Machines can only take work from people in factories.

C． In the future , there will be enough jobs for everybody

D． Machines will do the work instead of people

在（﹣1）³，（﹣1）²，﹣2²，（﹣3）²，这四个数中，最大的数与最小的数的和等于[ ]

A．6

B．﹣5

C．8

D．5

---Is Peter there?

---     , please. I'll see if I can find him for you.

A．Hold up

B．Hold on

C．Hold out

D．Hold off

混凝土是一种人工石材，常简写为（）。

A.人工石

B.砼

C.仝

D.磊

欧女士，21岁，患风湿性心脏病住某院行瓣膜置换手术，术中输同型全血3个，术后病情恢复顺利。 20天后患者恶心、厌油、腹胀、肝区疼痛，抽血查肝功能，谷丙转氨酶升高，乙肝表面抗原、e抗原、核心抗体阳性。

根据病人临床表现及抽血检查结果可诊断为

A．甲型肝炎，与输血有关，属医院感染

B．乙型肝炎，与输血有关，属医院感染

C．丙型肝炎，与输血有关，不属医院感染

D．丁型肝炎，与输血有关，不属医院感染

E．戊型肝炎，与输血有关，不属医院感染