The Secret Seven

C

解析：

[A] change v. 改变；交换

[B] chart vt. 绘制地图；记录

[C] charge vt. 收费

[D] challenge v. 质疑；驳斥

【句意】建筑师向我们收取了750美元的设计的费用。

故正确答案为[C]。

【真题例句】Railroads typically charge such "captive" shippers 20 to 30 percent more than they do when another railroad is competing for the business. 通常，铁路公司对这些“受牵制的”托运商的收费要比存在另一家铁路公司竞争时高出20%到30%。