B

    Mike works very long hours every day. He usually gets up at 17:00. He has a shower and makes his breakfast. What a funny time to make breakfast! After breakfast, he practices (练习) his guitar for ten minutes, then he puts on his jacket and goes to work. To get to work, he takes the No.17 bus to the Star Hotel. The bus usually leaves at 19:15. He works all night. People love to listen to him! He gets home at 7:00, and he watches the early morning news on TV. He goes to bed at 8:30, a tired but happy man. Can you think what his job is?

某同学进入泳池前以为池水很浅，踩下去后却有一种“踏空”的感觉，则水的实际深度要比看上去的深一些，其原因是(    )