(48~50)What can one person do to save Mother Earth?A lot! Just some easy changes can help make Mother Earth a better place to live. Here are some examples(例子):
1.    48      Don't ask your parents to drive you to school. You can walk, ride a bike, take a bus, or take the MRT.
2.   49     Bring your own cup to reduce trash.
3.Remember to turn off your TV, computer, and lights after use. 
      50     This way, we can have a cleaner and healthier earth.
【題組】48.
(A) Drive less.
(B) Don’t be late for school.
(C) Stop at a red light.
(D) Ride along the road.