[单项选择]
{{B}}TEXT F{{/B}}

Eight times within the past million years, something in the Earth’s climatic equation has changed, allowing snow in the mountains and the northern latitudes to accumulate from one season to the next instead of melting away each time. The enormous ice sheets resulting from this continual buildup lasted tens of thousands of years until the end of each particular glacial cycle brought a warmer climate. Scientists speculated that these glacial cycles were ultimately driven by astronomical factors: slow cyclic changes in the eccentricity of the Earth’s orbit and in the tilt and orientation of its spin axis. But up until around 30 years ago, the lack of an independent record of ice age timing made the hypothesis untestable.
Then in the early 1950s Emiliani produced the first complete record of the waxings and wanings of past glaciations. It came from a seemingly odd place. The seafloor single-cell marine organisms
A. Marine sediments have allowed scientists to amass evidence tending to confirm that astronomical cycles drive the Earth’s glacial cycles.
B. The ratio between two different isotopes of oxygen in seawater correlates closely with the size of the Earth’s ice sheets.
C. Surprisingly, single-cell marine organisms provide a record of the Earth’s ice ages.
D. The Earth’s astronomical cycles have recently been revealed to have an unexpectedly large impact on the Earth’s climate.

更多"{{B}}TEXT F{{/B}} Eight times wit"的相关试题:

[单项选择]

{{B}}TEXT F{{/B}}

Eight times within the past million years, something in the Earth’s climatic equation has changed, allowing snow in the mountains and the northern latitudes to accumulate from one season to the next instead of melting away each time. The enormous ice sheets resulting from this continual buildup lasted tens of thousands of years until the end of each particular glacial cycle brought a warmer climate. Scientists speculated that these glacial cycles were ultimately driven by astronomical factors: slow cyclic changes in the eccentricity of the Earth’s orbit and in the tilt and orientation of its spin axis. But up until around 30 years ago, the lack of an independent record of ice age timing made the hypothesis untestable.
Then in the early 1950s Emiliani produced the first complete record of the waxings and wanings of past glaciations. It came from a seemingly odd place. The seafloor single-cell marine organisms
A. water molecules containing oxygen-18 condense and fall as precipitation slightly sooner than those containing oxygen-16
B. the ratio of oxygen-18 to oxygen-16 in water vapor evaporated from oceans if different from that of these isotopes in seawater
C. growing ice sheets tend to lose their oxygen-18 as the temperature of the oceans near them gradually decreases
D. less water vapor evaporates from oceans during glacial periods and therefore less oxygen-18 is removed from the seawater

查看答案

[填空题]Eight times eight (make) ______ sixty-four.

查看答案

[填空题]In the past eight years USAID has experimented with and improved various methods to slow the spread of HIV/AIDS.

查看答案

[填空题]In the past eight years USAID has experimented a lot and improved various methods to slow the spread of epidemic.

查看答案

[单项选择]Text 3

Over the past decade, many companies had perfected the art of creating automatic behaviors-habits-among consumers. These habits have helped companies earn billions of dollars when customers eat snacks or wipe counters almost without thinking, often in response to a carefully designed set of daily cues.
"There are fundamental public health problems, like dirty hands instead of a soap habit, that remain killers only because we can’t figure out how to change people’s habit," said Dr. Curtis, the director the Hygiene Center at the London School of Hygiene & Tropical Medicine. " We wanted to learn from private industry how to create new behaviors that happen automatically. "
The companies that Dr. Curtis turned to-Procter & Gamble, Colgate-Palmolive and Unilever-had invested hundreds of millions of dollars finding the subt
A. reveal their impact on people’s habits
B. show the urgent need of daily necessities
C. indicate their effect on people’s buying power
D. manifest the significant role of good habits

查看答案

[单项选择]Text 3

During the past 15 years, the most important component of executive pay packages, and the one .most responsible for the large increase in the level of such compensation, has been stock-option grants. The increased use of option grants was justified as a way to align executives’ interests with shareholders’. For various tax, accounting, and regulatory reasons, stock-option grants have largely comprised "at-the-money options": rights to purchase shares at an "exercise price" equal to the company’s stock price on the grant date. In such at-the-money options, the selection of the grant date for awarding options determines the options’ exercise price and thus can have a significant effect on their value.
Earlier research by financial economists on backdating practices focused on the extent to which the company’s stock price went up abnorm
A. responsibilities increase very fast on the shoulders of the executives.
B. they account for a very important part in executives’ pay package.
C. shareowners intend to tie executives’ interests with their own.
D. shareholders expect executives to buy stocks at exercise price.

查看答案

我来回答:

提交