易引起再生障碍性贫血的药物是()
A.氯霉素
B.青霉素
C.庆大霉素
D.红霉素
E.四环素
参考答案:A
幼虫与成虫的形态结构和生活习性差异很大,这样的发育过程称为()。
It was between 1830 and 1835 ______ the modern newspaper was born.
A how B that C which D because