Bill and Tom ______like eating eggs. [ ]
A. does
B. don't
C. not
D.does
答案:B
后纵隔内不含有的结构为()
A.奇静脉
B.迷走神经
C.胸交感干
D.胸导管
E.膈神经
简述犬洗澡的目的。