[求助]高中英语单选题,谢谢了The chief reason for the population growth isn't so much a rise in birth rates____a fall in death rates as a result of improvements in medical care.A.and B.as C.but D.or,为什么选B,我觉得应该选C啊!求

[求助]高中英语单选题,谢谢了The chief reason for the population growth isn't so much a rise in birth rates____a fall in death rates as a result of improvements in medical care.A.and B.as C.but D.or,为什么选B,我觉得应该选C啊!求 英语单选题求助! 求助线性代数单选题, 高中英语单选求助 求助线性代数b3单选题 求助线性代数b2 单选题 高中英语单选题!别选了个答案就跑.one third the country__coverved with trees and the majority of the citizens __black people.选项A：is;are 选项B：is is 选项C ：are are 选项D：are is 高中英语求助 谢谢 英语单选题谢谢 一道高中英语代词单选题I have read three books and I want to read（.）A.another three books B.the other three booksc.more three booksD.more than three books我选的答案是B,但无法否定A选项求助谢谢 高中英语单选题The force of the explosion was _____ windows were blown out.A.such that B.as C.so that D.such 高中英语单选题21到29题 高中英语单选题,只需第29题= 高中英语单选题30到35题 高中英语单选题,请解释每个选项. 求助一道高中英语单选题Small as it is,the ant is as much a creature as _____ all other animals on the earth.A.areB.isC.haveD.do为什么?没看懂这句话的结构= 建筑制图3 单选题 求好人来解答 谢谢了 3个单选题谢谢