阅读理解。

     John and David are students. They are Mr. Green's sons. They get up early in the morning. They go

to school by bus after breakfast. Sometimes they have lunch at school. John likes hamburgers, chicken

and eggs. David likes vegetables and fruit. After lunch John goes to play volleyball and David goes to the

classroom. John likes playing computer games, but David likes singing.

根据短文内容，判断下列句子正（T）、误 （F）。

1. John is a student and David is a teacher.

2. Mr. Green is John and David's father.

3. John and David have lunch at home every day.

4. John likes vegetables and fruit.

5. David likes singing and John likes playing computer games.

有一帮同学为了测量篮球从教学楼三楼自由落下时地面对篮球的最大弹力，提出了以下四个方案，你认为可行的是（　　）

A．甲同学认为可以通过测量篮球的质量和落地后弹起的高度，然后根据动能定理可求最大作用力

B．乙同学认为把一张白纸平放到地面，然后把篮球的表面洒上水，让篮球击到白纸上，留下水印，然后把白纸放到体重计上，把球慢慢的向下压，当球和水印重合时，根据体重计的读数可知最大弹力的大小

C．丙同学认为根据牛顿第二定律及篮球落地前以及跳离地面瞬间速度可求最大作用力

D．丁同学认为可以把球直接打到普通指针式体重计上，直接读数即可