When were they invented and who invented them?具体看问题.For example :The abacus was invented in the six century by the Chinese.按照这个例句写umbrella binoculars camera bicyle~

When they were oh when they were young after they were born 和 when they were born We were happy when they left. They were all wet when they arrived at school.:Were they?Did they? They were singing whenwe were dancing可以用when They were surprised when they hear the news 同义句如题 They __an earthquake when they were traveling in Sichuan province 用when合并句子!They came home.They were wet. They were surprised when they heard the whisper.They were surprised ----- ----- the whisper. They were students when they were in their( )为什么是twenties? They were like olf friends and they were pleased when the plane landed safly 改错 some people hurt themselves when they were watching a sports programme.who were they? They were talking ( ) a film when come ( ) the room Who invented the aeroport?when were they born? they,what,doing,teacher,the,in,came,were,when when they were young 是什么意思?要准确的,谢了! What were they doing when the UFO l_____?