物资采购合同的当事人是（）。
A.承包人和发包人
B.供货方和发包人
C.供货方和采购方
D.发包人和采购方
参考答案：C
His efforts to raise money for his program were ______ because, no one showed any intention to take a cent out of their pockets.
A．in place
B．in sight
C．in effect
D．in vain
β系数越大，证券承担的系统风险越小。( )
