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.
A.Social media like skype.
B.Free online translation sites.
C.Face-to-face meetings.
D.Social networking tools.