C:C8H18(l)+25/2O2(g)===8CO2(g)+9H2O(g);ΔH=-5518 kJ/mol
A:2H+(aq)+SO42—(aq)+Ba2+(aq)+2OH-(aq)===BaSO4(s)+2H2O(l);ΔH=-57.3 kJ/mol
B:KOH(aq)+1/2H2SO4(aq)===1/2K2SO4(aq)+H2O(l);ΔH=-57.3 kJ/mol
D:2C8H18(g)+25O2(g)===16CO2(g)+18H2O(l);ΔH=-5518 kJ/mol
从方框中选择最佳选项完成对话, 有两项多余。
A. Don't worry.
B. Let's look for it together.
C. What's the matter?
D. Whose backpack is this?
E. It can't be mine.
F. You are welcome.
G. I think I might leave it in the reading room.
A: Anna, you look worried. ____
B: I can't find my backpack anywhere. Where can it be?
A: ____ Let's see where it might be.
B: ____But it isn't there.
A: What color is your backpack? ____
B: It's black and white.
A: Oh, look! Is this one yours?
B: No. ____ Mine is newer than this one.