I didn't believe I could make it u________ I got to the top of Mount Hua.
It has been five years ________ I saw my primary school classmate last time.
I was writing a diary w________ my mother was watching TV yesterday evening.
Keep on taking exercise, ________ you will become energetic.
We can enjoy the books in the reading room, ________ we can't take them out.
The city is covered with fog and haze more often than ever, ________ we must take actions to stop it.
