We go to school from Monday to Friday. We have four classes in the____and three in the afternoon. We have____things to do after class. On Monday and____afternoon we have P.E. On Wednesday morning some of us have a singing class. On____morning some have a drawing class. On Friday____we practice speaking English.

活动中，第一小组植树2棵，第二小组是第一小组的4倍，而第三小组又是第二小组的4倍，第三小组植树多少棵？

Sally used to be ___,but now she takes part in different activities and makes many new friends.

呼吸作用是生物的共同特征，其实质都是有机物____，释放____．