在TN—S系统中,除接地线和等电位连接线外,PE线表示()。
A.相线
B.中性线
C.工作零线
D.保护零线
参考答案:D
Managing e-business projects for the consulting firm, Milkem & Fleecem Inc. , has taken a heavy toll. You are waking up at night with cold sweats, and you are traveling so often your children have forgotten your name. Only the partners seem to be making money. Although you dream of prospering and opening an art gallery in Soho, the trendy district ill Manhattan, you need to complete a financial analysis of the payback period first. Such an analysis identifies the______.
A.ratio of discounted revenues over discounted costs
B.future value of money invested today
C.amount of time before net cash flow becomes positive
D.point in time where costs exceed profit
Charcot三联症是指()、()、()。