It was in 1949 ___new china was founded.为什么要填when,怎么样才能填that

It was in 1949 ___new china was founded.为什么要填when,怎么样才能填that it was in 1949 ___ China was founded. it was in 1949 that China was founded .这句话的 状语是什么 It was in 1949___the People's Republic of China was founded. when was the PRC founded?it was founded on ____. i bought it when i was living in the china,为什么这里要用was living it was in america ____she frist met Jack 填that when?which? was it during the first world war__he died?(that)为什么不填when? 填冠词_ People's Republic of China was founded on _ first of _ rthe communist party of china was founded in 1921,since when It was in the ___my father worked.填where 还是that ,为什么? when was the People's Republic of China founded ?