He had a Chinese lesson ____ Monday morning. [ ]
A.on
B.in
C.at
D.during
答案：A
—_________ model plane is this?
—I think it’s Jim’s. Look, his name is on it.
A．Who
B．What
C．Whose
D．Where
水平气流分选机的经验最佳风速为（）。
A.10m/s
B.20m/s
C.25m/s
D.30m/s
