A．The east-facing side
B．The west-facing side.
C．The north-facing side.
D．The south-facing side.
A．Reclaimed wood.
B．Recycled materials.
C．The massive amounts of concrete.
D．The special tiles used for converting energy from the sun.
A．Using email and social media.
B．Sending letters home.
C．Establishing computer training centers.
D．Offering babysitting service.