对尚未改造的互感器应每年检查顶部密封状况，对（）。
参考答案：老化
制度规定每月（）日交值勤记录、运转报表等。
A．1
B．10
C．20
D．21
When Bob was eighteen, he ______ going around with a strange set of people and staying out very late.
A．took to
B．took up
C．took for
D．took on
