下列乘法中,不能运用平方差公式进行运算的是[ ]
A.(x+a)(x﹣a)
B.(a+b)(﹣a﹣b)
C.(﹣x﹣b)(x﹣b)
D.(b+m)(m﹣b)
答案:B
阅读对话,判断正(T)误(F)。
Jenny: What's your favourite colour?
Kim: I like purple.
Li Ming: I like purple, too.
Jenny: You like the same colour. My favourite colour is green.
Danny: I like purple and green. My favourite colour is green, too.
( ) 1. Li Ming and Kim like different colours.
( ) 2. Jenny's favourite colour is green.
( ) 3. Purple is Danny's favourite colour.
( ) 4. Kim's favourite colour is purple.
在成人,出现休克体征时的出血量占总循环血量的()
A.10%
B.15%
C.20%
D.25%
E.30%