B analysis: investigate imperative sentences. Imperative sentences are used in two important sentence patterns: 1. "imperative sentences+and+declarative sentences indicating results" are used to describe affirmative conditions. 2. "imperative sentence+or (else)+ declarative sentence indicating the result" is used to describe negative conditions, or (else) means "otherwise; Otherwise. " Try to compare: hurry up, you will catch the train. If you hurry, you will catch the train. ); Hurry up, or you will miss the train. If you don't hurry, you will miss the train. )。 Where is the gym? It says below that you can find it by taking the elevator to the tenth floor. The gym is on the tenth floor, and it won't change because of subjective judgment, so the questioner will find it on the tenth floor, so choose B. Test center: test imperative sentence.