According to the passage, which of the following is an accurate statement concerning meteor streams?
A. Meteor streams and comets start out with smiliar orbits, but only those of meteor streams are perturbed by planetary gravittion.
B. Meteor streams grow as dust particles are attracted by the gravitational fields of comets.
C. Meteor streams are composed of dust particles derived from comets.
D. Comets may be composed of several kinds of materials, while meteor streams consitst only of large dust particles.
E. Once formed, meteor streams hasten the further disintegration of comets.
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处理方法是
A. 调磨左上后牙颊面
B. 调磨左下后牙颊尖颊斜面
C. 磨低左上后牙颊尖
D. 磨低左下后牙颠尖
E. 磨低右下后牙颊尖
李先生家庭的财务自由度为()。
A. 0
B. 0.5
C. 1
D. 2