单选题 According to the article, inventors used to secure patents on their inventions far ______ than they can now.
  • A. easiest
  • B. easier
  • C. most easily
  • D. more easily
【正确答案】 D
【答案解析】[解析] 语法：比较级 1．由空格后than可知，空格处应填入比较级结构。 2．空格处应填入副词来修饰动词used to secure，因此副词比较级D为正确选项。