(2)求证{bn}是等比数列;
参考答案:
—How many people are still leading ____ life under ___ poverty line in the world?
—Perhaps one fourth.
A.a, the
B.a, a
C.不填,不填
D.the, 不填
直通列车异地票的预售期为()天(特殊情况、动车组和直达列车除外)。
A.10
B.11
C.12
D.20