The second paragraph mainly demonstrates______.
A．space garbage's hazard towards people
B．that people produce waste of all kinds with large amount
C．whether people should take recycling into account
D．Ken Noguchi's five clean-up expeditions

未分类题When does Miralda-Escude estimate the first star appeared?A．75 million years ago.B．14 billion years ago.C．14 billion years after the big bang.D．75 million years after the big bang.

未分类题By mentioning an organization in San Diego, the author intends to______.A．encourage institutions to do interdisciplinary researchesB．state many institutions strive to study set environment's influence on humansC．prove that researches in neuroscience have been in popularityD．advocate that architecture schools should involve introductory neuroscience

未分类题We can learn from Paragraph 1 that______.A．the average adult sleeps one and a half hours less than last centuryB．24-hour entertainment offers those who can't sleep a way to kill timeC．lack of sleep may harm one's health and even threaten his her lifeD．people always don't have the incentive to get more sleep

未分类题How does the author feel about the current lack of technological literacy?

未分类题The underlined word in Paragraph 1 means______.A．obligationB．sleepC．hibernationD．vacation