下列是二元一次方程的是 [ ]
A．3x﹣2y
B．2x+1=3
C．4x2﹣2y=2
D．x+7y=0
答案：D
—Is your brother good at _____basketball?
—Yes, he is. [ ]
A. to play
B. plays
C. played
D. playing
当天基坑四周固定时，栏杆柱可采用钢管并打入地面（）
A、40~60cm
B、45~60cm
C、50~70cm
D、55~75cm
