在职攻硕英语考试

【单选题】The boy regretted having spent so much time playing when he ______
A．should have studied
B．had studied
C．was to study
D．must study

网考网参考答案：A
网考网解析：
[解析] 虚拟语气，这里考查的should have done(应该做而没有做)。故选A。 查看试题解析出处>>