Are these jeans made of denim?

这些牛仔裤是牛仔布做的吗？

同一单元的其他句子

• These shirts are made of cotton.这些衬衫是由棉花制成的。
• What is that sweater made of?那件毛衣是由什么制成的？
• The silk blouse feels very soft.这件丝绸衬衫摸起来很柔软。
• This scarf is not made of wool.这条围巾不是羊毛做的。
• The leather jacket is expensive.这件皮夹克很贵。