题目内容:
—I'm afraid we can't work out the math problem________the teacher helps us.
—That's true. It's too difficult.
A.if
B.unless
C.because
D.as soon as
参考答案:
答案解析:
—I'm afraid we can't work out the math problem________the teacher helps us.
—That's true. It's too difficult.
A.if
B.unless
C.because
D.as soon as