题干
—Please go and say hello to your aunt．She’s in the living room now．
—She has arrived! But when ______ she ______?
—She has arrived! But when ______ she ______?
A：will; arrive
B：did; arrive
C：had; arrived
D：has; arrived
答案(点此获取答案解析）
B
Ag（s）＋Fe3+（正反应放热）
