天安门广场每天升旗的时间与日出同步.下列节日中,升旗最早的是( )
A:“五一”国际劳动节
B:“六一”儿童节
C:“八一”建军节
D:“十一”国庆节
下列事例中,不是通过化学反应提供能量的是( )
A. Let's go.
B. Are these your shoes?
C. Let's play football.
D. They are on your feet.
E. What are they?
A:It's warm today.____
B:Great!____
A:Where are my shoes?
B:____
A:No.they aren't.
A:Look!____
B:Oh.I'm sorry.
已知热化学方程式:① C2H2(g) +52O2(g) == 2CO2(g)+H2O(l) ΔH1=-1301.0 kJ•mol-1② C(s)+ O2(g) == CO2(g) △H2=-393.5 kJ•mol-1③ H2(g)+ 12O2(g) == H2O(1) △H3 = -285.8 kJ·mol-1则反应④ 2C(s)+ H2(g) == C2H2(g)的△H为( )
①他一直有一个慈爱的母亲。____
②小彼得读着读着,感到羞愧万分。____
③他渐渐觉得自己似乎成了一个小商人。____