For years scientists have been worried about the effects of air pollution on the earth’s natural conditions. Some believe the air inside many houses may be more dangerous than the air outside. It
____ the youth ____ the rising sun at 8 or 9 o'clock am, Mao Zedong expressed his great hope for the young men. A. Comparing; withB. Compared; to C. Compared; with D. Comparing; to