有关咯血和呕血的鉴别下述不正确的是()
A.咯血不会出现黑便
B.呕血常为咖啡色
C.出血常混有痰液见于咯血
D.咯血的pH值呈碱性
E.呕血前往往有恶心
参考答案:A
用一根铁丝围成一个长15厘米、宽12厘米的长方形后,还剩8厘米,这根铁丝原来长多少厘米?
They are new students. Please______ them.[ ]
A. look
B. look like
C. look after
D. look out