—How old ____________ your cat?
—I think ____________ one.
A:is, it
B:are, it's
C:is, it's
D:are; is
— Hi, Mike! How's it going? — _______
当你感冒到医院里看病时,通常医生会问你是否头痛、咳嗽、鼻塞,然后给你测量体温。医生采取这些行动的直接目的是为了( )