这个封套是由柔性塑料制成的。

The cover is made of ___flexible plastic.

舞者需要拥有非常柔韧的身体。

Dancers need to have a very ___flexible body.

对于这项活动，灵活的身体和良好的敏捷性至关重要。

For this activity, a ___flexible body and good agility are crucial.