一个类可以从直接或间接的祖先中继承所有属性和方法。采用这个方法提高了软件的______。
参考答案：可重用性
_____ was known to all, William had broken his promise _____ he would give us a rise. [ ]
A. As; which
B. As; that
C. It; that
D. It ; which
皱缩印花
