单选题 In recent years, computer are being made ______.

A、 smaller and cheaper
B、 larger and more expensive
C、 more difficult to use
D、 to work more slowly

【正确答案】 A

【答案解析】解析：由文章第三句“But scientists and technicians have been making them smaller and cheaper while at the same time they have been easier to use”我们可以直接得到答案。