生物体能由小长大是通过（    ）         

如图是某人在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．在AB段有关肌肉的舒缩状态是（　　）

阅读短文，判断正误，正确的在题前打T，错误的打F 
Helen is an English school girl. She’s eleven years old. Now she and her parents are in Jinan. Her parents teach English in our school. They are very kind. Helen is a good pupil. She’s good at maths. We are good friends. She’s clever and beautiful . Now she can speak a little Chinese.
(1)Helen is from America.   ____ 
(2)Her parents are English teachers____ 
(3)Helen is in Beijing now.____ 
(4)She isn’t good at maths.____
(5)She can speak a lot of Chinese.____