单项选择题
A．Current issues in economics.
B．Choices faced by conservationists.
C．A recent biology lecture.
D．Topics for a research paper.
单项选择题 Norman Borlaug won a Nobel Prize for （）
单项选择题
问答题 Directions: For this part, you are allowed 30 minutes to write an essay commenting on the remark "A smile is the shortest distance between two people." You can cite examples to illustrate your point. You should write at least 150 words but no more than 200 words.