春秋战国时期有许多改革和变法,商鞅变法发生地在图中的代号是[ ]
答案:A
_____ a student, you should work hard every day. [ ]
A. In
B. To
C. With
D. As
辨别真假碘盐时,可将盐撒在淀粉溶液或切开的马铃薯切面上,以下判断正确的是()
A.如显出绿色,是真碘盐
B.如显出红色,是真碘盐
C.如显出蓝色,是真碘盐
D.如显出黄色,是真碘盐