使自然光通过两个偏振化方向夹角为60°的偏振片时,透射光强为i1,今在这两个偏振片之间再插入一偏振片,它的偏振化方向与前两个偏振片均成30°,问此时透射光强i与i1之比为多少?
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收养评估制度是《民法典》的一项新增制度,可以从源头保障收养行为更有利于被收养者。
A. 对
B. 错
Be ____. Don't drop the vase.
A. careful
B. funny
C. lovely
D. careless
Please give it ____ Miss Gao.
A. to
B. at
C. for
D. of
It's too hot. Please ____ your coat.
A. put on
B. take off
C. put down
D. take down