_________in the traffic jam，he got to school very late this morning．

There are a great number of natural resources in the desert, which remain to be ________.

________ around the Taimountain Park, the tourists from Hong Kong were taken to visit the Mei Langang Memorial Museum. 

–Where is Li Ping? –He’s _____ the library.

It is fairly common in Africa for     a group of musicians surrounded by others who also join in the performances.