四个英语短句中文区别1 not so much the decrease in deathrate as the fal

四个英语短句中文区别1 not so much the decrease in deathrate as the fall in birthrate2 no more the increase in birthrate than that in deathrate3 not much the drop in deathrate any more than the rise in birthrate4 as much the growth in birthrate as the decline in deathrate这四个中文分别怎么理解?