A:at
B:of
C:in
D:to
不改变分式的值,把0.1x+0.5y0.05x-0.05y的分子、分母各项系数化为整数得____ .
如图所示电路中,电源电压U=4.5V,且保持不变,定值电阻R1=5Ω,滑动变阻器R2的规格为“15Ω,0.5A”,电流表量程为0~0.6A,电压表量程为0~3V,为保护电路元件,R2接入电路的阻值范围是( )
用所给词的适当形式填空
(1)Autumn is a____(wonder)season.
(2)We all hope____(have)a long holiday.
(3)I____(buy)a new car the day before yesterday.
(4)I like doing some____(shop)with my parents.
(5)He did some____(read)last night.