表示流体流动形态类型可用雷诺数来表示，当流体流动属于层流时，雷诺数为（）A.Re≤1

Ireland has had a very difficult history. The problems started in the 16th century when English rulers tried to conquer(征服) Ireland. For hundreds of years, the Irish people fought against the English. Finally, in 1921, the British government was forced to give independence to the south of Ireland. The result is that today there are two “Irelands”. Northern Ireland, in the north, is part of the united kingdom. The Republic of Ireland, in the south, is an independent country.

In the 1840s the main crop, potatoes, was affected by disease and about 750,000 people died of hunger. This, and a shortage (短缺) of work , forced many people to leave Ireland and live in the USA, the UK, Australia and Canada. As a result of these problems, the population fell from 8.2 million in 1841 to 6.6 million in 1851.

For many years, the majority of Irish people earned their living as farmers. Today, many people still work on the land but more and more people are moving to the cities to work in factories and offices. Life in the cities is very different from life in the countryside, where things move at a quieter and slower pace.

The Irish are famous for being warm-hearted and friendly. Oscar Wilde, a famous Irish writer, once said that the Irish were “the greatest talkers since the Greeks”. Since independence, Ireland has revived(复兴) its own culture of music, language, literature and singing. Different areas have different styles of old Irish song which are sung without instruments. Other kinds of Irish music use many different instruments such as the violin, whistles, etc.

小题1:What does the author tell us in paragraph 1?

A．How the Irish fought against the English.

B．How Ireland gained independence.

C．How English rulers tried to conquer Ireland.

D．How two “Irelands” came into being.小题2:We learn from the text that in Ireland            .

A．food shortages in the 1840s led to a decline in population

B．people are moving to the cities for lack of work in the countryside

C．it is harder to make a living as a farmer than as a factory worker

D．different kinds of old Irish songs are all sung with instruments小题3:The last paragraph is mainly about          .

A．the Irish character

B．Irish culture

C．Irish musical instruments

D．a famous Irish writer小题4:What can be the best title for the text?

A．Life in Ireland

B．A Very Difficult History

C．Ireland, Past and Present

D．The Independence of Ireland

Nearly all the streets are in straight lines, _____ from east to west. Those _____ run from north to south are

called avenues. [ ]

A. running; that

B. run; who

C. running; who

D. run; that

已知y是x的反比例函数，它的图象经过点（-1，3），那么这个函数的解析式是______．

十个月患儿，轻咳伴发热半天，呕吐6次，不久水样便，开始为黄色后转为白色水样、量多黏液少，无腥臭，尿极少，于10月份就诊。体温39.5℃，面色苍白，皮肤弹性差，前囟及眼窝凹陷，哭泪少，咽充血，心肺正常，腹稍胀，肠鸣音活跃。

最可能诊断是()

A．轮状病毒肠炎

B．诺沃克病毒肠炎

C．致病性大肠杆菌

D．侵袭性大肠杆菌肠炎

E．产毒性大肠杆菌

液压油混入空气后可使液压系统产生气穴，油泵将发出异常声响，如不及时处理将损坏油泵。