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

Design methods and test process of nozzle closure made of hard foamed plastics for SRM are introduced.

介绍了固体火箭发动机喷管硬质泡沫塑料堵盖的设计方法与试验过程。

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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