【问】 In 1951，________ confirm her theory geneticist Barbara McClintock claimed that geneticinformation shifted from one chromosome to another.
 A. molecular biologists could before long
 B. could molecular biologists long before
 C. before long molecular biologists could
 D. long before molecular biologists could(TOEFL，86. 3)
 我一直区分不开before long与long before。请详析。
 【答】 before long意为“不久(之后)”(=soon，a little later)，long为名词，
 1. We shall finish before long.
 我们很快就会干完。
 2. Before long she came running behind me.
 很快，她就跑着追我了。
 3. Before long we got to the station.
 很快我们就到了车站。
 4. The petrol had nearly all been used up. Before long，the noise dropped completely andtheboat began to drift gently across the water. (New Concept English，Book 2，L. 86 ))
 汽油已差不多用完了，不一会儿马达声完全消失，汽艇开始缓慢地漂在水面上。
 5. The response to this competition was tremendous. Before long，biscuits of all shapesand sizes began arriving at the factory. (New Concept English，Book 3，L. 26)
 对这一比赛的反应是十分强烈的。不久，各种不同尺寸和不同形状的饼干开始送到工厂。
 long before(before为副词、介词或连词，long为副词)，意为“很久以前”，“早在……之前”。
 1. I had known her long before.
 很久以前我就认识她。
 2. I knew Smith long before I knew you.
 早在认识你之前我就认识史密斯了。
 3. She died long before the war.
 早在战前很久她就去世了。
 4. They began the experiment yesterday，but they had made preparation long before.
 他们昨天开始做实验，但早在这之前就已经作准备了。
 请做下面的英语试题：
 1. Preserved in rock，the bones of dinosaurs and the tracks made by these animals occur in many parts of the world and undoubtedly attracted attention before long they were understood. (TOEFL，87.1)
 2. “I have enjoyed my visit very much. ” “We hope to see you again before____. ”A. now B. this C. very long D. much time(TOEFL，74.6)
 3. ____her death in 1886，the poet Emily Dickinson had become a legend in her hometown of Amherst Massuchusetts.
 A. It was before long B. Before long
 C. When long before D. Long before(TOEFL，93.3)