强调句中,比如it was 9 when he came back.和it was at nine when he came back.都对吗

问题描述:

强调句中,比如it was 9 when he came back.和it was at nine when he came back.都对吗

第二句是强调句,第一句不是.但是两句话都对.
第一句的it 指代时间,when是个时间状语从句.
第二句是强调句.