一体化净水器自动反冲洗时间设置为（）一次。
A.24h
B.8h
C.12h
D.4h
参考答案：D
James has just arrived, but I didn't know he _____ until yesterday. [ ]
A. will come
B. is coming
C. was coming
D. comes
建筑平面图表示建筑面积、房间大小以及（）等位置和尺寸，墙厚度。
A.隔断
B.楼梯
C.门窗
D.屋顶
