有today的句子是什么时态

　　例句：

　　I vacuumed the carpets today.

　　我今天用吸尘器清洁地毯了。

　　Share prices moved ahead today.

　　今天的股票价格上升了。

　　Interest rates came down today.

　　利率今天下降了。

　　I haven't made a sweet today.

　　我今天没做甜点。

　　He let us off homework today.

　　他今天免了我们的家庭作业。