— The storybook is very interesting.
— I agree with you. I ______it twice already.
A:read
B:will read
C:have read
She ____ ____ the customers' complaints ____ every time.
图一表示的是某人在1个标准大气压下的一次平静呼吸中,肺内气压的变化曲线,图二是模拟呼吸作用示意图.请分析:
下列细胞器中,都不含磷脂的是 ( )