锅炉炉墙的散热量是夏天比冬天多。（）
参考答案：错
I failed in the job interview and only then _____ the importance of learning English well.
A．I realized
B．I had realized
C．did I realize
D．had I realized
周期特异性抗癌药：
A．氮芥
B．环磷酰胺
C．阿糖胞苷
D．巯嘌呤
E．博来霉素
