[单项选择]How many positive prime numbers are less than the integer n ？（）
(1)14＜n＜20
(2)13＜n＜17
A. 条件(1)充分，但条件(2)不充分．
B. 条件(2)充分，但条件(1)不充分．
C. 条件(1)和(2)单独都不充分，但条件(1)和条件(2)联合起来充分．
D. 条件(1)充分，条件(2)也充分．
E. 条件(1)和条件(2)单独都不充分，条件(1)和条件(2)联合起来也不充分．

[单项选择]How many integers 72 greater than 10 and less than 100 are there such that, if the digits of n are reversed, the resulting integer is n+9 ？（）
A. 5
B. 6
C. 7
D. 8
E. 9

[单项选择]If n and p are different positive prime numbers, which of the integers n⁴, p², and np has (have) exactly 4 positive divisors ？（）
A. n⁴only
B. p³only
C. n^ponly
D. n⁴andnp
E. p³andnp

[单项选择]Many peasants earn less than ______.


A. $ 60 a week
B. $ 2 a week
C. $1aday
D. $10amonth

[单项选择]For the positive numbers, n, n+1, n+2, n+4 and n+8, the mean is how much greater than the median ？（）
A. 0
B. 1
C. n+1
D. n+2
E. n+3

[单项选择]If n is a prime number greater than 3, what is the remainder when n² is divided by 12 ？（）
A. 0
B. 1
C. 2
D. 3
E. 5

[单项选择]If k is an integer greater than 44 and less than 51，then which of the following could be the product of 11 and k ？（）
A. 565
B. 550
C. 500
D. 484
E. 440

[单项选择]Old John smoked less than before.

[单项选择]Why will battery buses cost less than conventional buses in the long run
A. They will spread the capital cost over a long period.
B. They will be stronger and last longer.
C. They will use less fuel and cost less to maintain.
D. They will be charged at night when electricity costs less.

[单项选择]

Less than a week after a recent Russian airline tragedy, a female suicide bomber attacked a Moscow subway station; evidence indicates that Chechen separatists were likely the perpetrators of both attacks. Though the airline tragedy has been confirmed as a terror attack, the perpetrators re- main unknown. A group with links to Islamic jihadis in Pakistan has claimed responsibility for the attack. At the same time, forensic evidence suggests a notorious Chechen rebel group may be behind the attack. Regardless, the prevention of further terrorist attacks is fundamentally tied to Moscow’s deftness in handling grievances of the Muslim-majority state of Chechnya.
Despite the obvious suspicions about terrorist involvement, the Putin administration initially seemed determined to discount that supposition—perhaps to avert critiques of negligent airport security and failure to acknowledge Chechen problems mere days before a scheduled election. Instead, the administratio
A. want to calm down the public from horror events.
B. does not intend to acknowledge the pitfalls in its work.
C. have more reasonable examinations.
D. is indifferent to the events.