请从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的标号涂黑。
21. From the day we enter _____ university, we know _____ fierce competition for jobs is awaiting us upon graduation.
A. an, a B. /, a C a, / D. the, /
22. — Surely you can turn to David for help.
— _____ He is the last one you can rely on.
A. Get out of it! B. Sounds great!
C. I couldn’t agree more. D. It’s up to you.
