[单项选择]Human facial expression differ from those of animals in the degree to which they can be {{U}}deliberately{{/U}} contr011ed and modified.
A. sufficiently
B. noticeably
C. intentionally
D. absolutely

[单项选择]Human facial expression differ from those of animals in the degree to which they can be {{U}}deliberately{{/U}} controlled and modified.
A. sufficiently
B. noticeably
C. intentionally
D. absolutely

[单项选择]Human facial expressions differ from those of animals in the degree to which they can be ______ controlled and modified.
A. deliberately
B. consequently
C. originally
D. absolutely

[单项选择]Human beings differ from animals because they can
A. adapt to their environment.
B. control their environment.
C. adapt the environment to their need.
D. observe and understand their environment.

[单项选择] Human beings differ from animals _____ they can use language as a tool to communicate with each other.
A. for that
B. in that
C. for which
D. in which

[单项选择]Human beings differ mostly from all other animals in that they have the ability to ______ tools.
A. employ
B. tackle
C. deal
D. utilize

[单项选择]What makes human beings different from the rest of the animal world is their ability to ______.
A. learn a number of words
B. be taught a few grammatical structures
C. invent whole languages
D. to express their thoughts and feelings

[单项选择]

 Public goods are those commodities from whose enjoyment nobody can be effectively excluded. Everybody is free to enjoy the benefits of these commodities, and one person’ s utilization does not reduce the possibilities of anybody else’ s enjoying the same good. Examples of public goods are not as rare as one might expect. A flood control dam is a public good. Once the dam is built, all persons living in the area will benefit--irrespective of their own contribution to the construction cost of the dam. The same holds true for highway signs or aids to navigation. Once a lighthouse is built, no ship of any nationality can be effectively excluded from the utilization of the lighthouse for navigational purposes. National defense is another example. Even a person who voted against military expenditures or did not pay any taxes will benefit from the protection afforded. It is no easy task to determine the social costs and social benefits associated with a public good. Th
A. difficult procedure
B. daily administrative duty
C. matter of personal judgment
D. citizen' s responsibility