新鲜唾液的pH范围约为（）.
A.6.0～7.9
B.6.0～6.7
C.4.5～6.0
D.4.5～6.7
E.4.5～7.9
参考答案：A
. This race was her last chance to win a place on the national team so everything was __________.
A．dangerous
B．in stake
C．at stake
D．in charge
在亲子鉴定中首先应考虑什么血型系统？
