A-A+
The main reason for the population growth isn'
问题详情
The main 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．but
C．or
D．as请帮忙给出正确答案和分析，谢谢！
参考答案
正确答案：B
解析：not so/as…as…意为“不如……”，not…but…意为“不是……而是……”。
