成人英语三级考试

【单选题】But from the start of their experiments, the Wright brothers found that they needed money to pay ______ their research.


A．back
B．down
C．for
D．off

网考网参考答案：C
网考网解析：
pay for付款；pay off偿清。根据题意选C。pay不与其他两项搭配使用。 查看试题解析出处>>