i can't find the key.i must have left it in the car什么意思

i can't find the key.i must have left it in the car
我找不到钥匙。我一定是把它落在车上
例句:
1.
I can't find the key in my bag. I must have left it in my office.
在我的挎包里找不到钥匙，一定是忘在办公室里了。
2.
I can't find my wallet. I must have left it in my room.
我找不到我的皮夹。我一定把它忘在房间里了。

我找不到我的钥匙了，肯定是忘在车里了。

我找不到钥匙。我一定是把它留在车上了。