题干
— Hi! John, would you like to play football with us?
— Oh，I can’t. I ___ my lesson all the morning and still need half an hour.
— Oh，I can’t. I ___ my lesson all the morning and still need half an hour.
A：am reviewing
B：have been reviewing
C：have reviewed
D：reviewed
答案(点此获取答案解析）
B
H＝-571.6 kJ·mol-1，下列有关叙述不正确的 （ ）
