[单项选择]A period of climate change about 130,000 years ago would have made water travel easier by lowering sea levels and creating navigable lakes and rivers in the Arabian Peninsula, the study says. Such a shift would have offered early modern humans--which arose in Africa about 200,000 years ago—a new route through the formerly scorching northern deserts into the Middle East. The new paper was spurred by the discovery of several 120,000-year-old tools at a desert archaeological site in the United Arab Emirates. The presence of the tools—whose design is uniquely African, experts say—so early in the region suggests early humans marched out of Africa into the Arabian Peninsula directly from the Horn of Africa, roughly presentday Somalia. Previously, scientists had thought humans first left via the Nile Valley or the Far East.
"Up fill now we thought of cultural developments leading to the opportunity of people to move out of Africa," said study co-author Hans-Peter Uerpmann, a retired arch
A. aboriginal.
B. primitive.
C. luxuriant.
D. baking-hot.

更多"A period of climate change about 13"的相关试题:

[单项选择]A period of climate change about 130,000 years ago would have made water travel easier by lowering sea levels and creating navigable lakes and rivers in the Arabian Peninsula, the study says. Such a shift would have offered early modern humans--which arose in Africa about 200,000 years ago—a new route through the formerly scorching northern deserts into the Middle East. The new paper was spurred by the discovery of several 120,000-year-old tools at a desert archaeological site in the United Arab Emirates. The presence of the tools—whose design is uniquely African, experts say—so early in the region suggests early humans marched out of Africa into the Arabian Peninsula directly from the Horn of Africa, roughly presentday Somalia. Previously, scientists had thought humans first left via the Nile Valley or the Far East.
"Up fill now we thought of cultural developments leading to the opportunity of people to move out of Africa," said study co-author Hans-Peter Uerpmann, a retired arch
A. The cultural improvement caused the relocation.
B. Cultural development is crucial to human society.
C. The essence of the migration is the environment.
D. The discovery has changed our view completely.

查看答案

[单项选择]
Passage One

About four years ago, Kerry Sturgill found herself at a career crossroads: Should she stay in an industry populated by extroverts(外向型的人) or jump ship to a more reflective place where introverts like her were in the majority
Career counselors had told her to get out of the highly extroverted public relations fields " so you can be happy and do what you are. " Among the less fast-paced areas they pointed to: art, scientific research, data analysis.
Such a move is definitely the right road for many introverts struggling to fit into an extroverted workplace.
So, just what is an introvert anyway It’s someone who is energized by thought and reflection, while extroverts are energized by socializing. Introverts naturally need to think before they speak. Extroverts use the speaking process to figure out what it is they want t
A. introverts should try to avoid working in a highly extroverted environment
B. introverts should try to change themselves to fit into an extroverted working environment
C. extroverts should work in less fast-paced areas such as art and scientific research
D. introverts can be happier if they can find jobs in the field of public relations

查看答案

[单项选择]

About fifty years ago, plant physiologists set out to grow roots by themselves in solutions in laboratory flasks. The scientists found that the nutrition of isolated roots was quite simple. They required sugar and the usual minerals and vitamins. However, they did not require organic nitrogen compounds. These roots got along fine on mineral inorganic nitrogen. Roots are capable of making their own proteins and other organic compounds. These activities by roots require energy, of course. The process of respiration uses sugar to make the high energy compound ATP, which drives the biochemical reactions. Respiration also requires oxygen. Highly active roots require a good deal of oxygen.
The study of isolated roots has provided an understanding of the relationship between shoots and roots in intact plants. The leaves of the shoots provide the roots with sugar
A. quite natural
B. sugar, minerals and vitamins
C. some rare vitamins
D. organic nitrogen compounds

查看答案

我来回答:

提交