从每小题的A、B、C、D四个选项中，选出可以填入空白处的最佳选项，并在答题卡上将该选项涂黑。
11. It is clear that ______little money he earns can hardly support _______family as large as his.
A. the；a B. a；the C. /；a D. /；the
12.---Have you got enough members?
--- Mary says she will join us ______ the salary meets her expectations..
A. until B. if C. though D. unless
13.---What a golden opportunity you missed! It means you’ll have to wait for another ten years.
---But I _______ to Beijing on business!
A. travel
C. was traveling B. would travel
D. have traveled
