投资者从取得土地开始，通过在土地上的进一步投资活动是指（）。
A．房地产管理投资
B．房地产置业投资
C．房地产开发投资
D．房地产经营投资
参考答案：B
Read and judge. 阅读对话，判断正(T)误(F)。
Danny: What do you want to do?
Jenny: Let's go shopping, Danny.
Danny: OK. Where?
Jenny: Hmmm. Let's go to the silk shop.
Danny: The silk shop! No, thanks! I don't want to buy silk.
Jenny: OK, then let's go to the clothes shop. I want to buy a new dress.
Danny: Forget it! I don't want to buy a new dress.
( ) 1. Jenny wants to go shopping.
( ) 2. Danny wants to buy a new dress.
( ) 3. Danny doesn't want to buy silk.
( ) 4. Jenny wants to buy a new dress.
振荡一个周期的长度称为超声的（）
A.周期
B.速度
C.波长
D.频率
E.以上都不是
