Please keep______ secret that he’ s decided to give up his present position.

_______ was known to them all that William had broken his promise ______ he would give each of them a gift. 

. _____ can be enjoyed until you have a deep understanding of the low-carbon lifestyle.

We shouldn’t take_____ for granted that our parents will take care of us forever.

 --How is_______ going with you?　　　-- So so.