I was writing a letter ,He was reading a newspaper(用适当的连词连成一个复合词语)

问题描述:

I was writing a letter ,He was reading a newspaper(用适当的连词连成一个复合词语)

NO1:I was writing a letter ,while he was reading a newspaper
NO2:I was writing a letter ,whereas he was reading a newspaper
NO3:I was writing a letter ,whilst he was reading a newspaper