下列物质中属于碱的是（ ） A．纯碱[Na2CO3] B．烧碱[NaOH] C． 发布时间：2017-05-12 04:12 │ 来源：www.tikuol.com 题型：选择题 问题： 下列物质中属于碱的是（ ）A．纯碱[Na2CO3]B．烧碱[NaOH]C．乙醇[C2H5OH]D．碱式碳酸铜[Cu2（OH）2CO3]
题型：选择题 根据表格，选择正确答案。1988至1990年， 一个名为“人口危机委员会”的组织对世界上100个大城市进行了调查。请根据下面12个主要大城市的调查表回答问题。 Population(million)(%) of income spent on foodPersons per room(%) if houses with water and electricityTelephones per 100 people(%) of children in high schoolTokyo 28.7 18 0.9 100 44 97 Mexico City 19.441 1.9946 62New York 17.4160.5995695Sao Paulo 17.250 0.81001667Osaka16.8180.6984297Seoul 15.8342.01002290Moscow13.2331.310039100 Bombay12.9574.285549 Calcutta12.8603.057249 Buenos Aires 12.4401.3861451 Los Angeles11.5120.5943590 London 11.0 240.6 100 50 581. Of the following cities, people live in ____ spend least of their income on food. [ ]A. Mexico City B. Buenos AiresC. Calcutta D. Bombay 2. Which city has the most people? [ ]A. New York. B. Moscow.C. Tokyo. D. London. 3. The number of the students studying in high schools in Tokyo out of 100 students is the same as that of _____. [ ]A. Seoul B. Sao Paulo C. Calcutta D. Osaka 4. In which city do all the houses have water and electricity? [ ]A. London. B. Los Angeles. C. New York. D. Bombay. 5. It is the most difficult for people in _____ to make a phone call. [ ]A. Sao Paulo B. Mexico City C. Bombay D. Calcutta 查看答案
题型：选择题 剪刀撑斜杆的接长应采用搭接或对接，采用搭接时，（）A.搭接长度不应小于1mB.端部扣件盖板的边缘至杆端距离不小于100mmC.应采用不少于2个旋转扣件固定D.端部扣件盖板的边缘至杆端距离不小于150mmE.应采用不少于3个旋转扣件固定 查看答案