单选题 In the history of religions and cultures, nature worship as a definite and complex system of belief or as a predominant form of religion has not been well（documented）.

单选题 A highly adapted hibernator, such as a ground squirrel, will（ ）underground at the appropriate season, reduce its body temperature drastically within a few hours, and become dormant.

单选题 NATO troops were sent into Bosnia to oversee the implementation of the agreement, which calls for the（ ）of the republic into Muslim-Croat and Serb areas.

单选题 Having to ask for assistance was（ ）for many men who had thought of themselves as self-sufficient and breadwinners for their families.

单选题 When people are said to have bad grammar, the inference is that they（ ）the rules of accepted usage associated with the language they speak.

单选题 Slum structures are characterized by（ ）materials, lack of underground sewerage, unsanitary conditions, and tenements of one-room apartments.

单选题 America's secondary school adjusted itself more and more to preparing the young for everyday living, and it went to great（ ）to accommodate the generality of young America with courses in driving, cookery, carpentry, and the like.

单选题 A person's religious beliefs and forms of worship are matters of strictly private conscience, into which no government act or official may（ ）.

单选题 Essential to all automatic-control mechanisms is the feedback principle, which enables a designer to（ ）a machine with the capacity for self-correction.