5米=______分米=______厘米400平方厘米=______平方分米22

         In many countries around the world May 1 is a holiday. Labour Day, or Workers' Day, is an international holiday that honours working men and women, and the jobs they do.

         During the late 1880s, in many parts of the world, people worked for fourteen to sixteen hours a day in factories, and earned very little money. In the United States and Canada, working people got together to try to make their workplaces better. These groups of people formed unions (团体). The union leaders asked company directors for shorter work days and higher salaries (工资), but many of them refused to accept their ideas.

         On May 1, 1886, men and women in the United States and Canada stopped work and marched through cities and towns to try and force bosses to let them work an eight-hour day. In the city of Chicago, several people died in fights with the police. Over the next few years, people in cities around the world stopped working every May 1 to honour workers everywhere. By the early twentieth century, the first of May was a national holiday in many countries.

         In the United States and Canada, May 1 is not a holiday. North Americans celebrate Labour Day on the first Monday in September. Today in the Unites States, Labour Day is mostly about having fun. People enjoy a long weekend, and often celebrate by having barbecues or picnics with friends or family. In many parts of the Unites States, Labour Day is also the last day of summer vacation, and the students return to school the next day.

1. People celebrate Labour Day to honour       .   

A. union leaders  

B. working people  

C. people died in fights  

D. workers and their jobs

2. People had to work for over fourteen hours        a day. 

A. in 1886  

B. in the 1880s

C. in the 19th century  

D. in the early 20th century

3. In Paragraph 2, the underlined word “them” refers to (所指) “      ”.  

A. workers  

B. union leaders  

C. company directors

D. policemen

4. Workers in USA and Canada stopped work for        on May 1, 1886. 

A. shorter work days  

B. higher salaries  

C. better workplaces   

D. an eight-hour working day

依次填入下面一段文字横线处的语句，衔接最恰当的一组是(　　)

相比国外卫星导航系统，北斗系统目前独具导航和短报文通信相结合的特色，______，______，______。以海洋渔业为例，“我在哪里”，能够使渔民通过船载设备实现自主定位；“你在哪里”，使岸上的人通过监控知道渔船在什么地方。而在沙漠、山区、海洋等人烟稀少的地区进行搜索时，______，______，______。北斗卫星导航系统应用前景十分广阔。

①已在我国经济社会多个领域得到了广泛应用

②也能知道“你在哪里”

③有效缩短救援搜寻时间，提高抢险救灾时效

④北斗卫星导航系统除导航定位外

⑤既能知道“我在哪里”

⑥还能通过短报文通信功能，及时报告所处位置和灾情

A．⑤①②⑥④③

B．⑤②①④⑥③

C．②①④⑥③⑤

D．②③④⑥⑤①

尿激酶、链激酶（）。

A.脑保护剂

B.抗凝治疗

C.溶栓治疗

D.血液稀释疗法

E.脑代谢活化剂

两圆柱相交，其表面交线称为（）。

A、截交线

B、相贯线

C、空间曲线

D、平面曲线

固定矫治器中带环最常用于

A．尖牙

B．中切牙

C．第一磨牙

D．侧切牙

E．双尖牙