以下为信息资源的主要经济特征表现的是（）。
A.作为生产要素的人类需求性
B.使用方向的可选择性
C.共享性
D.稀缺性
参考答案：A, B, C, D
以下不是瓜萎功效的是（）。
A．润肺化痰
B．清肺化痰
C．宣肺祛痰
D．利气宽胸
E．滑肠通便
句型转换.
1. She does her homework at home. (改为否定句)
She her homework at home.
2. He's reading when it is raining. (就画线部分提问)
he when it is raining?
3. How's the weather in Beijing? (改为同义句)
the weather in Beijing?
4. I'm having a great summer in London. (改为一般疑问句并作否定回答)
you a great summer in London?
No, .
5. It's cloudy today. (就画线部分提问)
today?
