单选题Select 3 people from 4 couples to form a group. Two people of one couple can not be selected at the same time. How many ways of selection are there?
单选题How many integers between 1 and 2,000 will be the square of an integer and also be the cube of an integer?
单选题现在有1元人民币4张，2元人民币2张，10元人民币3张，从中至少取出1张，最多取出9张，共可以配成多少种钱数?
单选题Points -2, xandy, 2, not shown in the figure above, are in quadrants Ⅲ and Ⅱ, respectively, in which quadrant is pointx, y?
单选题Let’s be a set of outcomes and let A and B be events with outcomes in S．Let-B denote the set of all outcomes in S that are not in B and let PAdenote the probability that event A occurs．What is the val
单选题From 1900 until the 1930s, pellagra, a disease
单选题Aroca City currently funds its public schools
单选题Most banks that issue credit cards charge
单选题If the price of the clothes decreases from $25 to $20, what is the percent decrease in price?
单选题Tanco, a leather manufacturer, uses large
单选题Although Ackerburg's subway system is currently
单选题Generally scientists enter their field with the
单选题在一个数列中，第一项和第二项分别是2和4，随后的每一项都是前面各项的和，如果第10项的值是n，那么第15项是多少?
单选题The regular price of a certain car is $10,000. If the price is discounted by 20 percent during the first week and the reduced price is then discounted by 5 percent during the next week, how much money
单选题把苹果放进n个抽屉，至少放多少个苹果才能够保证至少有一个抽屉里有两个或者两个以上苹果?
单选题Meat from chickens contaminated with salmonella
单选题从两个集合{8、9、10、11、12、13、14}和{15、16、17、18、19}中分别随机挑出一个来并且相加，问它们的和最多有几种?
单选题If x and z are integers, is x + z2 odd?1 x is odd and z is even. 2 x-z is odd.
单选题If x, y are positive integers, is xy divisible by 4?1y+2 is divisible by 4.2x+2 is divisible by 4.
单选题有一棵树，高为10米，现在在其五等分fifths和三等分thirds处被做标记，如果这棵树要在标记处被截断，下面哪一个给出了所有不同的被截后树的长度?