是定語(yǔ)從句.因?yàn)橄刃性~是the black cat在從句中做saw的賓語(yǔ).關(guān)系代詞that代替先行詞在從句中做賓語(yǔ).從句意思：這就是我上次看到的那只貓.如果是強(qiáng)調(diào)句.應(yīng)該是這樣的：It was the black cat that I saw last time.強(qiáng)...去掉后變?yōu)?I saw the black cat last time. 不是也通嗎it was the black cat that I saw last time.去掉it was ,,that后變?yōu)?the black cat I saw last time.強(qiáng)調(diào)句前后時(shí)態(tài)要一致。定語(yǔ)從句可以不一致具體看語(yǔ)境