jeans是用is还是are

　　We can't wear jeans at work.

　　我们工作时不准穿牛仔裤。

　　The jeans stretch to provide a perfect fit.

　　这条牛仔裤有弹性，可以完全贴身。

　　Jeans are not appropriate for a formal party.

　　正式聚会上穿牛仔裤不合适。

　　These jeans are too long in the leg.

　　这条牛仔裤的裤腿太长。