单项选择题
To be a good salesman, the most important thing is to （）.
A．learn from different kinds of people B．understand what people are thinking C．see what people usually do in daily life D．watch what changes people have made
单项选择题 Only ______ making investigations ______ have the right to speak.
单项选择题 Thinking that you know ______ in fact you don"t is not a good idea.
单项选择题 Mrs. White became a teacher in 1985. She ______ for twenty years by next summer.
