[单项选择]While attempting to look into the case,（）
A. he found it was difficult
B. the case was difficult
C. it happened that the case is difficult
D. difficult as the case

[单项选择]While fully employed, men look for______.
A. visual entertainment that requires imagination in their leisure
B. opportunities to create either with their hands or with their minds in their leisure
C. something that will help them relax in their leisure
D. creative hobbies in their leisure

[填空题]Chinese enterprises are attempting to go abroad because they hope that overseas experience will enhance their own marketing and management expertise.

[单项选择]David: Since attempting to preserve every species that is currently endangered is prohibitively expensive, the endangered species whose value to humanity is the greatest should be accorded the highest priority for preservation.
Karen: Such a policy would be unsound because it is impossible to predict the future value of a species, nor is it always possible to assess the present value of species whose contributions to humanity, though significant, are indirect.
Which of the following is the main point of Karen’s reply to David
A. Although it would be desirable to preserve all endangered species, doing so is not economically feasible.
B. Even if the value to humanity of a given species is known, that value should not be a factor in any decision on whether to expend effort to preserve that species.
C. Species whose contributions to humanity are direct should have a higher priority for preservation efforts than species whose contributions to humanity are only indirect.
D. Since the methods for deciding which species have the most value to humanity are imperfect, informed decisions cannot be made on the basis of the assessment of such value.
E. (E) The preservation of endangered species whose value to humanity can be reliably predicted is more important than the preservation of species whose value for humanity is unpredictable.

[填空题]IBM researchers are attempting to warm up human-computer relationships. For example, IBM, International Business Machines, has been working on getting computers to recognize human{{U}} (36) {{/U}}, such as an arm wave to move a{{U}} (37) {{/U}}object on screen. Recently, the company’ s researchers have gone a{{U}} (38) {{/U}}further by training a computer to recognize human{{U}} (39) {{/U}}To demonstrate their progress, IBM{{U}} (40) {{/U}}out Pong, a{{U}} (41) {{/U}}head without body that can react to human facial expressions with a smile or a{{U}} (42) {{/U}}Pong uses a camera to{{U}} (43) {{/U}}your gestures in pain or anger or frowning and uses software to interpret what it sees. But don’t expect your computer to start grinning at you any time soon.{{U}} (44) {{/U}}In the meantime, you can get a taste of the future by playing with basic gesture-recognition technology on your own Windows PC.{{U}} (45) {{/U}}Cybernet’s $40 Headhunter software can track and trans