题干
By the time I reached home , my parents ____ the dinner for me already
A：had cooked
B：cooked
C：have cooked
D：cook
答案(点此获取答案解析）
A
By the time I reached home , my parents ____ the dinner for me already
A：had cooked
B：cooked
C：have cooked
D：cook
缓解甲、乙三角洲地区的能源供应紧张问题，两地都很重视开发利用的新能源是
