[单选题]对泄水管和排水管如有足够厚度要求,对外径为180mm的管子,厚度应不小于____mm。
A.10
B.9.5
C.8
D.9

[多选题]钢轨接头预留轨缝应根据（）经计算确定。
A.钢轨长度
B.当地历史最高及最低轨温
C.更换钢轨或调整轨缝时的轨温
D.气温

[不定项选择题]Questions 76-80 refer to the following information. Disagreements among economists are legendary, but not on the issue of free trade. A recent survey of prominent economists both conservative and liberal concluded that an economist who argues for restricting international trade is almost as common today as a physician who favors leeching. Why the International free trade, economists agree,, makes possible higher standards of living all over the globe. The case for free trade rests largely on this principle: as long as trade is voluntary, both partners’ benefits, otherwise they wouldn't trade. The buyer of a shirt, for example, values the shirt more than the money spend, while the seller values the money more. Both are better off because of the sale. Moreover, it doesn’t matter whether the shirt salesman is from the United States or Hong Kong （or anywhere else）. The vast majority of American manufactures face international competition. This competition forces companies to improve quality and cut costs. By contrast, protectionism encourages monopoly, lower quality and higher prices. Americans pay an enormous price for protection over $60 billion a year, or $1000 for a family of four. Thanks to protectionism, for example, American consumers pay twice the world price for sugar. Free trade also makes the world economy more efficient, by allowing nations to capitalize on their strengths. The United States has an advantage in food production, for instance, while Saudi Arabia has an advantage in oil. The Saudis could undertake massive irrigation to become self-sufficient in food, but it is more economical for them to sell oil and purchase food from us. Similarly, we could become self-sufficient in petroleum by squeezing more out of oil shale. But it is much less costly to buy some of our oil from Saudi Arabia. Tarde between our two countries improves the standard of living in both. Protectionism is both wasteful and unjust. It taxes most heavily the people who can least afford it. Thus, tariffs that rise the price of shoes burden the poor more than the rich. Despite the powerful case for free trade, the United States and the rest of the world have always been protectionist to some degree. This is because free trade benefits the general public, while protectionism benefits special interest group, which are better organized, better financed and more informed. To make matters worse, much of what we hear on this issue is misinformation spread by the special interests themselves. According to the free trade principle, the author suggests that _____.
A.Saudi Arabia build its own food industry.
B.Saudi Arabia import food from U. S.
C.U.S. become self-sufficient with its oil.
D.U.S. explore its oil shale.

[多项选择]旅行社责任保险的主体包括（）
A. 旅游局
B. 保险人
C. 投保人
D. 被保险人与受益人

[判断题]发生七级人身、电网、设备和信息系统事件，应按资产关系或管理关系上报至上一级管理单位
A.正确
B.错误

[多项选择]