赞题库-背景图

单项选择题

When did the technique of hearing test become standardized

A．Two years ago.
B．Three years ago.
C．Five years ago.
D．A decade ago.

<上一题目录下一题>

热门试题

单项选择题What suggestions did the experts offer to stereo manufacturers

A．Providing a warning light when the sound is too loud.
B．Improving the quality of personal stereo systems.
C．Standard heating test should be set up.
D．Restricting the use of personal systems.

单项选择题Maximum alertness was normally achieved ______.

A．form8-11 a.m. and9-12p.m.
B．between3 p.m. and5 p.m.
C．form9-11 a.m. and9-11p.m.
D．between8-20a, m. andT-9p.m.