题干
My teacher said my composition was too long. I must ______ to about 3,000 words.
A：cut it off
B：cut it u
C：cut it dow
D：cut it out
答案(点此获取答案解析）
C
A：cut it off
B：cut it u
C：cut it dow
D：cut it out
CO2(g)+H2(g) ΔH=-43kJ/mol，在850℃时，K=1，今在某密闭容器中充入1.0molCO、3.0molH2O、1.0molCO2、xmolH2，下列说法不正确的是（ ）