They were made from hard plastics and that's why they were very breakable.

它们的制作材料是硬塑料，这就是它们极其易碎的原因。

youdao

The other types of plastic are less likely to be collected and recycled, although that is slowly changing and some cities, such as San Francisco, take all hard plastics.

其它类型塑料被收集、回收的可能性较小，不过这个情况正在慢慢地改变，像三藩市这样的一些城市回收所有（类型）硬塑料。

youdao

As well as being ideal for Magnets, it will also bond Glass, Rubber, Ceramics, Wood, Metal, Leather, most Hard Plastics, Fabric, Cardboard, Chipboard, Dry Concrete and Masonry.

除了作为理想的磁铁，它也将债券玻璃，橡胶，陶瓷，木材，金属，皮革，最硬质塑料，织物，纸板，纤维板，清水混凝土和砖石。

youdao

It's going to go straight into a hole in the ground, because the hard plastics that make up things like the big six pint milk bottles have some value.

BBC

And then there's glass and hard and soft plastics, and paper, and card and tin foil.

BBC

Over the years, he's been working on a technique called "plastination" that replaces the water and fat inside a body's tissues with polymers -- sticky, hard-drying plastics.

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