1. A challenging new area in inorganic chemistry is .........the role of transition metals in the biochemical catalysts called enzymes. a. that of understanding b. to have understanding c. the understanding d. understanding that that 应该是说 this challending new way,后面的of表示是修饰这个way的，这个用排除法就可以做出来，D不对，是因为that the role....就不成一个完整句子，called enzymes是做定语的。 2. Initially introduced in 1852, the gyroscope consists a spinning device, usually in the form of a wheel, that exhibits strong angular momentum. consist of , not "consist". 固定搭配 3. Paleoantheropologists examine fossil remains of extinct primates, while physical anthropologists concern with ethology study the behavior of primates in their natural settings. 无论是concern with or concern about，一定都是be concerned with, be concerned about. 这里concern的形式应该是concerned. answer: 1.a 2. D 3. B 可为什么呢？ | 
