You should ___________ here at 7:00 this morning. But you arrived at 8:00.You were late.
A:have arrived
B:arrived
C:arrive
D:had arrived
如图所示,连入电路中的电阻R1、R2、R3允许通过的最大电流分别为I1、I2、I3,且I1>I2>I3,则此部分电路中允许通过的最大电流是( )
如图,点A、B、C、D都在⊙O上,∠ABC=90°,AD=3,CD=2,则⊙O的直径的长是____
____ C2H2+____O2 点燃__ ____CO2+____H2O
____ Fe2O3+____CO 高温__ ____CO2+____Fe.
天若有情天亦老,____。
司法保护是专门维护违法犯罪未成年人合法权益的一项重要举措。( )