使用错别字，往往曲解了概念本身的含义，下列名词用字正确的是 [ ]
A．甲笨
B．乙稀
C．乙酸乙脂
D．正戊烷
答案：D
-- You know who came to our school yesterday?
-- Professor Smith? We once met at a conference.
-- ______. He came and gave a wonderful speech.
A．How did you know that?
B．That was good news.
C．Got it!
D．Well Done!
一项系统评价综合可25篇应用口服阿司匹林预防冠心病的随机对照试验结果：实验组冠心病发生率12%，对照组发生率18%。
该试验组绝对危险降低率为（）。
A.6%
B.50%
C.33.3%
D.15%
E.3%
