第1个回答 2011-01-18
1/问句 Did he send the sample to you yesterday?
2/ 陈述句 He sent the sample to you yesterday.
第2个回答 2011-01-18
did he mail you the samples yesterday already?
第3个回答 2011-01-18
Had he sent you the sample yesterday ?
第4个回答 2011-01-18
The sample has been sent to you. It was sent yesterday.