B
It is easy to overlook the rolethat your body plays in influencing your mood（情绪）.when you are 49 ,you may find yourself blaming work pressures or an unknown future.However,it could just be that you’ve been sitting behind you desk too long.
One way to improve your mood is 50 .Psychologically,it provides you with a break from the stresses in your life .Also,in the process,you may aim for 51 goals,like a mew personal running record or a better body shape.The achievement of a particular goal makes you feel good and contributes to your 52 .That is why exercise has been shown to 53 your self-respect.
You do not have to train yourself 54 to feel the psychological benefits of exercise.What really matters is 55 ,not intensity（强度）of your exercise.You can try walking for 30 minutes five times per week or simply gardening on weekends.
49.A.ill B.poor C.unhappy D.unsuccessful
50.A.play B.communication C.sleep D.exercise
51.A.clear B.present C.common D.early
52.A.ability B.relationship C.confidence D.business
53.A.tear down B.build up C.set aside D.give out
54.A.hard B.everywhere C.carefully D.late
55.A.time B.length C.form D.frequency