问题
选择题
.When she came out, Mary looked a bit tired because she _____the house.
A．cleaned
B．was
C．had cleaned
D．had been cleaning
答案
答案：D
搜题请搜索小程序“爱下问搜题”
.When she came out, Mary looked a bit tired because she _____the house.
A．cleaned
B．was
C．had cleaned
D．had been cleaning
答案：D
