plastic things可数吗

The stool had a torn, red plastic seat.

这条无靠背凳子有一个破了的、红色的塑料坐部。

I was sitting on a wobbly plastic chair.

我当时正坐在一把摇摇晃晃的塑料椅子上。

She bent and picked up a plastic bucket.

她弯腰拎起一个塑料桶。