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?
单选题The interview is an essential part of a
单选题On a trip of 408 miles, Tom travels the first 160 miles in 4 hours. At what rate must he travel for the remainder of the trip in order to average 34 miles per hour for the entire trip? in miles per ho
单选题Plantings of cotton bioengineered to produce its
单选题A，B两个人合作生产一批零件，6天可以完成任务。A先做5天后，因事外出，由B接着做3天，共完成任务的710，如果A单独做这批零件需要多少天?
单选题X, Fare positive integers and X+2Y=16. What’s the value of X?1X＞Y2X＞4, Y＞4
单选题If d=123.4546, and d1 is the number obtained by rounding d to the nearest hundredths, then d1=
单选题One hour after Tom started walking from X to Y, a distance of 45 miles. Bob started walking along the same road from Y to X. If Tom’s walking rate was 3 miles per hour and Bob’s was 4 miles per hour,
单选题Five integers between 10 and 99，inclusive，are to be formed by using each of the ten digits exactly once in such a way that the sum of the five integers is as small as possible．What is the greatest pos
单选题If rs=s, what is the value of r+s?1r=425=0
单选题有7个数字：a，a，b，b，c，c，d，从中任取两个，问这两个数字相同的概率?
单选题下面哪一个不可能为多少天的小时数目?
单选题X和Y是从集合{1，2，3，4，5，6}中随机挑选出来的不相等的两个数，问在所有的和中，X+Y是完全平方数的概率?
单选题0到9这10个数字能够组成多少个没有重复数字的三位数?