市场三要素?
参考答案:
人口、购买力、购买欲望
Students in English-speaking countries usually address their man teacher ‘sir”, but __________ their woman teacher “madam”.
A.seldom they address
B.do they seldom address
C.seldom do they address
D.they seldom do address
10kV及35kV系统发生单相接地时,在什么情况下可采用人工转移接地的方法处理?