答案是B。
1. We’ll have a picnic in the park this Sunday _____ it rains or it’s very cold.
A. since B. if C. unless D. until
2. My brother is really ____. He often works in his office far into the night.
A. open-minded B. hard-working C. self-confident D. warm-hearted
3. ---- I just can’t stop worrying about the result of the job interview.
----_____. There’s nothing you can do now but wait.
A. Relax B. Go ahead C. Go for it D. Good luck
4. _____ their hats into the air, the fans of the winning team let out loud shouts of victory.
A. To throw B. Thrown C. Throwing D. Being thrown