一、单项选择（共20小题；每小题1.5分,满分30分） 从A、B、C、D四个选项中,选出可以填入空白处的最佳选项。
1. He tried his best to solve the problem, __________ difficult it was.
A. however B. no matter C. whatever D. although
2. At this time tomorrow __________ over the Atlantic.
A. we’re going to fly B. we’ll be flying
C. we’ll fly D. we’re to fly
