题目内容
According to Figure 2, the presence of which of thefollowing minerals in a metamorphic rock would beleasthelpful in determining that rock’s grade？
查看答案
搜索结果不匹配？点我反馈
更多问题
Scientist 1
The object was a comet, a body made of ices (such asfrozen water or methane) and dust. Most of this cometarymaterial is volatile(easily vaporized) and low in density.Friction in Earth’s atmosphere heated the comet to a tem-perature at which it exploded, high above the ground. Themajority of the ices and dust were vaporized in the explo-sion, which explains why no crater was formed at the siteand why no large, identifiable fragments of the object werefound. An asteroid would not have been completelydestroyed. Intact asteroid fragments that reached theground would have created one or more craters uponimpact and left behind recoverable pieces. Evidence showsthat the object decelerated rapidly before it exploded.Because of their low density, comets are capable of suchrapid deceleration, whereas high-density objects, such asasteroids, are not.
Scientist 2
The object was a stony asteroid. As it entered Earth’satmosphere, its high speed created a large air pressure dif-ference between the area just in front of the asteroid andthe area just behind the asteroid. The large pressure differ-ence eventually exceeded the structural strength of theasteroid. The asteroid flattened, decelerated rapidly due tothe dramatic increase in its surface area, and fragmentedbefore reaching the ground. This fragmentation would haveappeared like an explosion. Calculations show that a cometbetween 10m and 100m in diameter would explode at analtitude much higher than 8km, but a stony asteroid of thatsize would fragment at or near an altitude of 8km.Recovery of large asteroid fragments is difficult due to thearea’s boggy soil; however, small, glassy fragments wererecovered and are believed to be melted and resolidifiedpieces of the asteroid.
Which of the following phrases best describes the majorpoint of difference between the 2 scientists’ hypotheses？
“创造力”与“创新”为一体的两面，相辅相成，而创意的产生有赖于创造力智能的发挥，创意的绩效取决于创新成果的展现。()
所谓系统思维，是指不受某种固定的逻辑规则约束而直接领悟事物本质的一种思维形式。()
参考答案：错误
派件时客户未签字，业务员回到营业网点后，（）代替客户签字。
微信支付 
支付宝支付