Question

英语这几道选择题（30-34）怎么做，要有解析，谢谢！

30.Operations which ______ patients exhausted（筋疲力尽）and in need of long periods of recovery time are now making them feel relaxed and comfortable.

A. leave B. had left C. left D. will leave

31.Hours of playing violent video games can affect the way the brain works, ______ damage to certain cells of brain and slowing brain activity.
A. to cause B. causing C. cause D. caused

32.It is generally accepted that Chinese were the earliest ______ football while the Europeans established the modern rules for football.
A. played B. playing C. to play D. having played
33. There is little doubt ______ you will be able to judge truth and error if you have confidence in yourself.
A. that B. who C. when D. if
34. It really seemed ages ______ the police arrived and cleared away the damaged cars.
A. before B. after C. since D. when

Answer 1

26. 解析：先将原式因式分解，得到5x2、4x5、3x10、2x17、（a x b） 5、4、3、2、a构成公差为1的等差数列，所以 a=1； 2、5、10、17、b，两两做差后，得到3、5、7、（b-17），由此可知b-17=9，所以b=26，所以（ a x b ）=1 x 26 = 26。