Americans
问题It is found that many Americans are not doing enough to care _____ their teeth.A、／B、f
ItisfoundthatmanyAmericansarenotdoingenoughtocare_____theirteeth.A、/B、forC、aboutD、with
问题About three－fourths of Americans cannot see the Milky way because _____ man－made ligh
Aboutthree-fourthsofAmericanscannotseetheMilkywaybecause_____man-madelight.A、/B、byC、forD