pH7.4Tris-HCl溶液（）。
A.包被液
B.稀释液
C.洗涤液
D.底物溶液
E.IA.中所用上述各种缓冲液的主要成分是
参考答案：C
He was excited because he _____ his father at Chinese chess. [ ]
A. won
B. played
C. beat
进一步检测不选用
A．心电图B．尿量C．中心静压D．血细胞比容E．颅脑CT
