507.Tony,come down and help me with the heavy box!
Come on!I _______ all day long.Get Peter to do that!
A.work
B.had been working
C.had worked
D.have been working
508.Gina has a sweet tooth and loves meat more than anything else.
No wonder she _______ weight so fast.
A,gains
B.gained
C.had gained
D.is gaining
507.答案是D;考查动词的时态在具体语境中的应用。根据语境和下文all day long暗示，另外此处主体语境是现在时，选D。
508.答案是D;gain weight增加体重。根据上下文得知，由于爱吃甜食和肉，体重不断增加。
