B .
C .
D .
— Oh, I didn't notice it.

①throw away a pencil without completely using it
②collect waste things for recycling
③go to school by kike instead of by car
④turn off the tap while brushing our teeth
⑤keep the lights on day and night
① obey the traffic(交通) rules
② be careful of passing cars and buses
③ run fast after others
④ not read the messages on our mobile phones
⑤ play basketball with our friends
① regularly open the windows of our house for better ventilation(通风)
② not share towels (毛巾)with our family members
③ go out of our way to pay more attention to our temperature
④ hardly ever exercise
⑤ neither eat nor buy wild animals
B .
C .
①take exercise to keep healthy
②keep reviewing lessons all night to get good grades
③go to school without breakfast
④have plans for study
⑤open the window and take in fresh air as often as possible