He ________ sleep, although he tried to,
题型：选择题
问题：
He ________ sleep, although he tried to, when he got on such a hunt for an idea until he had caught it.
A．wouldn’t
B．shouldn’t
C．couldn’t
D．mustn’t
He ________ sleep, although he tried to, when he got on such a hunt for an idea until he had caught it.
A．wouldn’t
B．shouldn’t
C．couldn’t
D．mustn’t