A:cup
B:buy
C:play
一粗细均匀的镍铬合金丝,电阻为R.现将其长度拉伸为原来的2倍,它的电阻变为( )
A.Taste the soup, Kitty. B. What do youhear? C. Smell the noodles, Ben.
D.What colour is the frog? E. It’snice.