对于动词或者形容词，只使用经批准的形式。

All revision numbers and dates shall be removed from pages.

The flight crew can use the flight director commands to control the attitude of the airplane.

The cover, when down, is a guard for the switch in the ON position.

Controls in the flight compartment permit selection of temperature and flow rates.

Tighten the coaxial connectors (hand tight plus 1/8 turn)

It has a single shaft and operates at a constant speed.

Care must be taken not to damage the firewall cover.

Two semicircular flappers control air flow.

It is necessary to clean the filter periodically.

The seat height lock mechanism controls seat height.