21. X-rays are also called Rontgen rays_______the discoverer who first put them to use.  
A.in place of
B.in honor of来源：www.examda.com
C.in case of
D.in view of

22. Telecommunication developments have enabled people to send messages_______television, radio and electronic mail.  
A.past
B.across
C.via
D.amid

23. Technology has_______the sharing, storage and delivery of information, thus making more information available to more people.   
A.functioned
B.facilitated
C.finished
D.furnished

24. The philosophy class began with twenty students but three_______after the mid-term exam.   A.dropped out
B.kept up
C.picked up
D.turned out

26. An intimate and _______knowledge of how you are doing in the customer's eyes is critical.   
A.optional
B.subsequent
C.objective
D.subordinate

27. Long _______ to harmful pollutants is most likely to lead to a decline in health.  
A.use
B.exposure
C.contact来源：www.examda.com
D.touch

28. The architectural differences may_______confusion or discomfort for the foreign travelers.   
A.cause
B.impress
C.vary
D.describe

29. _______being fun and good exercise, swimming is a very useful skill.   
A.Instead of
B.Owing to来源：www.examda.com
C.Rather than
D.Apart from

30. Even at discounted prices, these powerful AIDS drugs are far beyond_______ for most of the world's 40 million HIV-infected people.   
A.comprehension
B.imagination
C.reach
D.control