Who _____ the music first? Tom did. [ ]
A. hear
B. heard
C. listened
D. listen to
答案:B
慢性粒细胞白血病化疗首选的药物是( )。
A.苯丁酸氮芥B.泼尼松C.长春新碱D.白消安E.环磷酰胺
燃烧热的传播有哪三种方式?