He must be from America, _____? [ ]
A. isn't he
B. must be
C. needn't he
D. is he
答案:A
溃疡性结肠炎的典型X线征象是()
A.充盈缺损
B."杯口"征
C."鸟嘴"征
D."鹅卵石"征
E."铅管"征
抢救氰化物中毒最有效的办法是尽早使用()
A.硫代硫酸钠
B.亚硝酸钠
C.小剂量美兰
D.先用亚硝酸钠,再用硫代硫酸钠
E.先小剂量美兰,再用硫代硫酸钠