《物业管理条例》明确规定对业主委员会实行( )制度。
A．备案
B．审批
C．核准
D．登记
参考答案：A
关于都江堰的作用最准确的说法是[ ]
A．防洪排水
B．防洪蓄水
C．防洪灌溉
D．蓄水防旱
Stephen Hawking can't walk or even speak, ________ he has become very successful. [ ]
A. but
B. and
C. or
D. then
