Best covers

#1: informal
#2: formal
#3: informal
#9: formal
#10: environmental
#11: environmental
#13: environmental
#15: informal
#19: environmental/ informal
#21: environmental
#22: formal
#23: informal
#24: environmental/ informal
#26: informal
#27: informal
#28: environmental
#29: informal
#30: environmental
#31: formal
#32: informal
#35: informal
#36: formal
#37: informal
#39: formal
#40: environmental
#41: informal