单选题Images from ground-based telescopes are
单选题Gortland has long been narrowly self-sufficient
单选题Which of the following most logically completes
单选题Studies of the political orientations of 1,055
单选题If x＜y＜z and y-x＞5．where x is an even integer and y and z are odd integers，what is the least possible value of z-x?
单选题The first four digits of the six-digit initial password for a shopper’s card at a certain grocery store is the customer’s birthday in day-month digit form. For example, 15 August corresponds to 1508 a
单选题If y = 2x+1, what is the value of y-x ?1 22x+2 = 642 y=22x-1
单选题What is the value of x?1 4x+1 + 4x = 3202 x2 = 9
单选题When a certain stretch of highway was rebuilt and straightened，the distance along the stretch was decreased by 20 percent and the speed limit was increased by 25 percent．By what percent was the drivin
单选题3+32+33+…+3k，k为多少时，和能够被6整除?
单选题How many positive integers n have the property that both 3n and n3 are 4-digit integers?
单选题Rolling a number cube with faces numbered 1 to 6 similar to a 6-sided die is an experiment with 6 possible outcomes: 1, 2, 3, 4, 5 or 6. If we toss two number cubes simultaneously, what is the possibl
单选题共有A，B，C，D，E 5个元素要放在有顺序的5个位置上，要求满足条件：A在B之前，B在C之前A＞B＞C，同时还要满足D在E的前面D＞E，问一共有多少种排法?
单选题Which of the following cannot be expressed as the sum of two prime numbers?
单选题1．234 1．243 1．324 . . . . . . +4．321 The addition problem above shows four of the 24 different integers that can be formed by using each of the digits 1，2，3，and 4 exactly once in each integer． What is
单选题If x is a prime number, what is the value of x?141＜x＜482x+1 is a multiple of 4.
单选题If two liters of a solution that is 15 percent salt will be added to 5 liters of a solution that is 8 percent salt, what percent salt will the resulting solution contain?
单选题A rope 60 meters long is cut into three pieces A, B, C, If piece A is 12 meters longer than piece B, piece B is 9 meters shorter than piece C, then what is the length, in meters, of the shortest piece