It _____ me five minutes to walk to school. [ ]
A. takes
B. spends
C. costs
D. pays
答案:A
变压器的空载电流基本上就是变压器的激磁电流。( )
儿童常见的“四病”是哪些?()
A.肺炎
B.贫血
C.佝偻病
D.腹泻