1. We were all there when the accident occurred.
A. happened
B. broke
C. spread
D. appeared
2. It took me exactly a week to complete the work.
A. do
B. achieve
C. improve
D. finish
3. He achieved success through hard work.
A. reached
B. reaped
C. attained
D. took
4.They have made up their mind to give up smoking.
A. tried
B. attempted
C. agreed
D. decided
5. They have given up the hope to save their friends from drowning.
A. ended
B. abandoned
C. built
D. strengthened
答案：1.答案选A. occur是单义词， 其基本词义为发生。因此A是答案。
2.答案选D.complete作为动词使用时， 其词义为完成， 因此D是答案。Do是多义词，其常见词义为做, 尽力, 制作。
3.答案选C.achieve的基本词义为实现， 获得， 因此C是答案。
4.答案选D.make up ones mind是固定搭配结构， 其含义为决心， 决定， 因此D是答案。
5. 答案选B. give up是放弃， 因此B是答案。