题干
After trying hard, they _______ the hope of finding an effective way to solve the problem.
A：abandoned
B：released
C：discouraged
D：resigned
答案(点此获取答案解析）
A
A：abandoned
B：released
C：discouraged
D：resigned
、
，若
，则
”是一个真命题
、
”的否定是：“
、
”