在风力发电机电源线上，并联电容器的目的是为了（）。
参考答案：提高功率因素
为什么要进行矿井瓦斯等级鉴定？
Salesperson A’s compensation for any week is $360 plus 6 percent of the portion of A’s total sales above $1,000 for that week. Salesperson B’s compensation for any week is 8 percent of B’s total sales for that week. For what amount of total weekly sales would both salespeople earn the same compensation ？（）
A.$21，000
B.$18，000
C.$15，000
D.$4，500
E.$4，000
