青蛙个体发育的过程是 ( )
A：蝌蚪→成蛙
B：蝌蚪→幼蛙→成蛙
C：受精卵→蝌蚪→幼蛙
D：受精卵→蝌蚪→幼蛙→成蛙
150×40=____ 603×24=____ 596×26=____
下列行为中有利于建设良好班集体的是（ ）
There is an interval of ten minutes between the two classes，________we can have a rest.
