A:
B:
C:
D:
下列各句中,划线的成语使用恰当的一项是 ( )
△ABC中,角A,B,C所对的边分别为a,b,c,已知sinA+sinC=psinB且 ac=14b2 .若角B为锐角,则p的取值范围是( )
China is a country that has made great ____(contribute) to mankind in history.