课堂上，老师演示了酵母菌发酵的小实验．使挤扁的气球胀大的气体是（ ）
A：水蒸气
B：酒精气
C：氧气
D：二氧化碳
A: Listen! Is it Tina singing in the next room?B: No, it __________ be her. She is still in Shanghai.
—You________go to a doctor. I'll take you to hospital.
例句：光与影有着和谐的旋律，如梵婀玲上奏着的名曲。
