There _____ nothing wrong with your computer. [ ]
A. is
B. are
C. was
D. were
答案:A
在“大鱼吃小鱼,小鱼吃虾,虾吃水草”这一食物链中,大鱼属于( )
A.生产者
B.消费者
C.分解者
D.分解者和消费者
胸部损伤后咯血或痰中带血提示()
A.气胸
B.血胸
C.肺或支气管损伤
D.食管损伤
E.损伤性窒息