题干
By the end of last month, we ______already ______ our lessons.
A：has, finished
B：have, finished
C：had, finished
D：will, finish
答案(点此获取答案解析）
C
By the end of last month, we ______already ______ our lessons.
A：has, finished
B：have, finished
C：had, finished
D：will, finish
所成的比为1，则
分向量
所成的比为
