______ come into leaf or bloom is obviously a sign of spring. 

 I remember _________the factory owed a small workshop and two machines.

 Mo Yan has published dozens of novels, of ________ some are very popular among Chinese readers, Red Sorghum, for example.

After entering university, we will reach a point in our studies       _________we need to decide how to arrange our timetable efficiently and independently. 

This is the museum ___ we visit yesterday.