About 2000 years ago,the world's population was p------- about 250 million.

When __the great book About 2000 years ago.(write ) from 400 years ago和about 400 years ago 区别 it was about 100 years ago Two years ago.about i love you. About 2000 years ago,the world's population was p------- about 250 million. 3.He started to collect shells about 4 years ago.( 用for about 4 years 替换4 years ago) about English grammar ,例句three years ago 中的ago是修饰three years __ three years ago.A,since B,for C,about When the first elephants appeared about 40 million years ago. An old lady talked about hei life many years ago. Little Jimmy is about seven years old.保持句意不变Little Jimmy ________ _______ about seven years ago. We came here __.A.for three years B.about three years C.for about three years D.three years ago 句型转换 1.Your teacher left here about an hour ago.2.The old men died there years ago. We now know the first dinosaurs_____(出现)about 230 million years ago. We now know the first dinosaurs ___ [apper]about 230 million years ago. About 400 years ago,Galileo proved that the earth__(go)around the sun. the first bicycle appeared about two hundred years ago.这句话的意思! he has worked in the factory_____five years ago 1.for 2.at 3.since 4.about