1. Parents often faced the ______ between doing what they felt was good for the development of the child and what they could stand by way of undisciplined noise and destructiveness.
A. paradox
B. dilemma
C. junction
D. premise
 
2. Some biologists argue that each specifically human trait must have arisen gradually and erratically, and that it is therefore difficult to isolate definite ________ in the evolution of species.
A. fluctuations
B. manifestations
C. predispositions
D. milestones




  1.B
【句意】父母们经常面临这样的进退两难：一方面得做自己认为对孩子成长有益的事情；另一方面又得忍受孩子毫无拘束的吵闹和破坏行为。
【解析】名词词义辨析。paradox“悖论，自相矛盾（的说法）”；dilemma“困境，进退两难”；junction“连接，接合，交叉点”；premise“前提，假定”。由关键信息“doing what they felt was good”和“what could stand”可推知“进退两难”符合，由此知B项正确。
 
2.D
【句意】一些生物学家认为，每一种特定的人类特征应该是逐步地且不规律地出现的，这些科学家也因此认为在物种进化过程中很难孤立明确的（人类特征的）重要阶段。
【解析】名词词义辨析题。fluctuation“起伏，波动”；manifestation“表现；显示；示威运动”；predisposition“倾向；癖性；（易患某种病的）体质”；milestone“ 里程碑，划时代的事件；重要阶段”。由句中关键词“each specifically human trait must have arisen gradually and erratically每一种特定的人类特征应该是逐步地且不规律地出现的”、“it is therefore difficult to isolate definite…因此很难孤立明确的……”以及“in the evolution of species物种进化过程中”的对应知“重要阶段”符合语境，故D项正。