在国际贸易中，出口商或进口商及其银行向对方保证履行合同义务的担保叫做
A．借款担保
B．投标担保
C．履约担保
D．抵押担保
参考答案：C
______ get older, the games they play become increasingly complex.
A．Children
B．Children, when they
C．As children
D．For children to
砂岩体
