托福考试

【单选题】 The color and pageantry, keen rivalry, and high level of competition both contribute to the great worldwide interest in the Olympic Games.

【单选题】 An unconsolidated aggregate of silt particles is also termed silt, ___________ a consolidated aggregate is called siltstone.
A．( which
B．( why
C．( whereas
D．( whether

【单选题】 Over the centuries, __________ that try to explain the origins of the university.
A．( although many theories
B．( many theories
C．( have many theories been
D．( there have been many theories

【单选题】 Transistors (exhibit) a high amplification factor, operate without (distorted) over a (wide frequency) range, and can be made (extremely small).
A．exhibit
B．distorted
C．frequency
D．extremely small

【单选题】 The chief (commercial) source of bromine is ocean water, from (what) the element is extracted by (means of) chemical (replacement) by chlorine.
A．commercial
B．what
C．means of
D．replacement