16.（ ）

(单选题)Tianjin is one of ______ cities in China. (单选题)Chinese people make ______ a rule to get together in the Spr (单选题)At ______ end of the show, Yu Hua will perform the violin co (单选题)Hiking by oneself can be fun and good for health. It may als (单选题)Teachers have to constantly update their knowledge in order (单选题)In the face of this situation, the manager of the company sa (单选题)Below ______ an article about advertisements ______ by a stu (单选题)The number of the officers who ______ cars ______ increasing (单选题)Is it he or you ______ in charge of the job and supposed to (单选题)—I want to do business via online platforms like Alibaba.—__