下面关于旅游饭店业务特点的叙述，正确的是（）
A、饭店产品的无形性
B、饭店业务的单一性
C、饭店业务的稳定性
参考答案：A
China is known ______ greatly in terms of its cultural values over the past few years.
A．to change
B．having changed
C．changing
D．to have changed
两条对角线相等的四边形是矩形。[ ]
