【单选题】关于家庭电路各组成部分的作用 , 下列说法中正确的是 ( )
【多选题】How to keep your hands in the right position?
A.
You can put them on your lap.
B.
Bever keep them in your pockets.
C.
Don't squeeze them too tightly if you place your hands on the table.
D.
Leave them flat with your palms down.
【简答题】设x∈N + 时f(x)∈N + ,对任何n∈N+有f(n+1)>f(n)且f(f(n))=3n, (1)求f(1); (2)求f(6)+f(7); (3)求f(2012).
【简答题】在直流电路中电感元件相当于() A短路 B开路 C通路 D不一定
【简答题】在直流电路中电感元件相当于(),电容元件相当于()。
【单选题】—How do you look after your goldfish? —They need clean water, and remember not to _____ with your hands.