法律规定骑摩托车的人必须戴头盔。

Motorcyclists are required by law to wear a ___helmet.

她骑自行车时为了安全总是戴头盔。

She always wears a ___helmet for safety when cycling.

作为安全装备的一部分，他买了一个新头盔。

As part of the safety gear, he bought a new ___helmet.