关于赫尔希和蔡斯“噬菌体侵染细菌”的实验中，下列说法正确的是（ ）
“竭泽而渔，岂不得鱼，而明年无鱼”体现了可持续发展的（ ）
I brush my teeth and wash my face. ____
I go to school.____
What do you do after breakfast? ____
I go to school on foot. ____
What do you do before breakfast? ____
How do you go to school? ____
A、B是两个质量完全相同的实心长方体，轻轻放入水中后，静止时如图所示，则下列说法正确的是（ ）
I brush my teeth and wash my face. ____ I go to school.____ What do you do after breakfast? ____ I go to school on foot. ____ What do you do before breakfast? ____ How do you go to school? ____
