One evening when it was swarm, I stayed awake ___________ until half past eleven in order to have a good look at the moon by myself.

One evening when it was swarm, I stayed awake ___________ until half past eleven in order to have a good look at the moon by myself.

A．on average        B．on purpose        C．on sale           D．on schedule

One evening when it was so warm, I stayed awake _________ until half past eleven in order to have a good look at the moon by myself.

One evening when it was so warm, I stayed awake _________ until half past eleven in order to have a good look at the moon by myself.

A．on average        B．on purpose        C．on sale           D．on schedule

One evening when it was so warm, I stayed awake _________ until half past eleven in order to have a good look at the moon by myself.

1. A.
   on average
2. B.
   on purpose
3. C.
   on sale
4. D.
   on schedule