将十六进制数1ABH转换为十进制数是
A.112
B.427
C.428
D.540
参考答案:B
解析: 转换算式是:1ABH=1*162+10 *16+11-160=427。
—I called you yesterday evening, but there was no answer.
—Oh, I am sorry. I ______ dinner at my friend's home. [ ]
A. have
B. had
C. was having
D. have had
直接人口的食品应当有小包装或者使用无毒、清洁的包装材料。 ( )