证券公司进行证券自营买卖，其收益主要来源于低买高卖的价差以及代理业务手续费。
参考答案：错
24. In their hearts, some children think it is their parents’ business to earn money and________to spend it.
A．they
B．them
C．their
D．Theirs
急性血源性骨髓炎最常见的致病菌是
A．白色葡萄球菌
B．真菌
C．金黄色葡萄球菌
D．大肠杆菌
E．肺炎双球菌
