A-A+
From the passage we learn that ______.A．it is
问题详情
From the passage we learn that ______.
A．it is much cheaper to buy an old patent than a new one
B．products are actually inventions which were made a long time ago
C．an invention will not benefit the inventor unless it is reduced to commercial practice
D．patent experts often recommend patents to others by conducting a search through dead patents
参考答案
正确答案：C
解析：文章第五段第二句：It is their reduction to commercial practice，either through necessity or dedication or through the availability of new technology，that makes news and money．与C项意义相符合。
