四面楚歌是指哪种压力？（）
A、继时性叠加压力
B、破坏性压力
C、同时性叠加压力
D、单一性生活压力
参考答案：C
用所给词的适当形式填空。
1. Look! Whose _____ (Walkman) are these? Perhaps they are the twin’s.
2. Is there an _____ (electric) shop in your town?
3. Amy wants to buy some presents for _____ (they).
4. Do you understand the _____(mean) of the new world?
5. Do you like to have cold _____ (drink)?
肺大疱（）
A．X线胸片病变部位透亮度增加
B．X线胸片病变部位肺纹理消失
C．两者均有
D．两者均无
