Environmental protection ______ everyone's support.

A．Lightning can happen even if there is no cloud.
B．Lightning won’t do harm to people’s health.
C．Lightning can travel sideways.
D．Lightning can strike very far.

A．Birds find their way by the stars at night and by the sun during the day.
B．Birds can tell the differences between real sky and artificial sky.
C．Birds can see the stars and would move when the stars change position.
D．Birds always fly to the sides of the cage.