is kept是什么時態

　　All our glass and China is kept in the cupboard.

　　我們所有的玻璃器皿和瓷器都放在碗櫥里。

　　For reasons of security the door is always kept locked.

　　為了保證安全，門總是鎖著的。

　　The suspect is being kept under observation.

　　嫌疑人正受到監視。

　　A skeleton staff of 20 is being kept on.

　　留下了20名骨干人員。

　　Next year's collection is still being kept under wraps.

　　明年的時裝系列仍在保密之中。