—Children today find it hard to focus on study.
—Exactly,as they________so many fun things to do.
A:found
B:have found
C:had found
D:will find
如图所示,在甲、乙两地之间沿直线架设两条输电线,由甲地向乙地输电,两条输电线总电阻为10Ω,甲地电源的电压为220V不变,下列说法正确的是
若函数f(x)=x+2a-1图象关于x=1对称,则实数a的值为( )
用CO通过下列方法可以合成甲醇。
①CO2(g)+2H2O(l) === CH3OH(g)+ 32 O2(g) ΔH1=+764.5 kJ·mol-1
②CO(g)+ 12 O2(g)===CO2(g) ΔH2=-283.0 kJ·mol-1
③H2(g)+ 12 O2(g)===H2O(l) ΔH3=-285.8 kJ·mol-1
下列有关说法正确的是( )
My brother broke the window ____(故意地)to enter the house.