题干
Henry must have stayed up last night, ________ he looks so tired and sleepy.
A：for
B：a
C：though
D：since
答案(点此获取答案解析）
A
A：for
B：a
C：though
D：since
nC(g)△H＞0生成物C的浓度随压强变化并建立平衡的关系图,则n值与压强p1、p2的关系正确的是 （ ）
