消化道溃疡的常见症状是（）
A.腹胀
B.上腹痛
C.消化道出血
D.恶心
E.呕吐
参考答案：B
下列选项中，不属于汉字编码的是（）
A．GB2312
B．ASCII
C．UCS
D．GB18030
John promised his doctor he _____ not smoke, and he has not smoked ever since. [ ]
A. might
B. should
C. could
D. would
