【正文】
So is he. B. So He is. C. So was he. D. So he was. 4. The population is______. It may be the greatest challenge (挑戰(zhàn) ) of the world today. A. reduced B. increased C. increasing D. reducing 5. In fact, many countries have _____ some effective (有效的) policies to control the population. A. carry out B. taken out C. c