—How _____ you?
—I ____ fine, thanks. [ ]
A. are, is
B. are, am
C. is, am
D. am, are
答案:B
对神经系统有毒性的药物是()
A.5-氟尿嘧啶
B.甲氨蝶呤
C.喜树碱
D.巯嘌呤
E.长春新碱