在税法要素中，对纳税对象总额中的一部分数额免予征税，只就减除后的剩余部分计征税款，被

氯解磷定解救有机磷酸酯类(农药)中毒是因为

A．能直接对抗乙酰胆碱的作用

B．能使失去活性的胆碱酯酶复活

C．有阻断M胆碱受体的作用

D．有阻断N胆碱受体的作用

E．能对抗有机磷酸酯分子中磷的毒性

治疗顽固性头痛，宜选用

A．全蝎、蜈蚣

B．石决明、决明子

C．天麻、钩藤

D．薄荷、荆芥

E．冰片、麝香

致猪出血性败血症的病原体是（）.

某客户上年度在银行国际结算量达3000万美元，且在海关、外管局及我行没有不良记录，现在银行申请开立90天远期信用证业务，按我行保证金收取的最低标准为（）.

A、10%

B、15%

C、20%

D、可以免收保证金

The ocean bottom—a region nearly 2.5 times greater than the total land area of the Earth —is a vast frontier that even today is largely unexplored and uncharted. Until about a century ago, the deep-ocean floor was completely inaccessible, hidden beneath waters averaging over 3,600 meters deep. Totally without light and subjected to intense pressures hundreds of times greater than at the Earth’s surface, the deep-ocean bottom is a hostile environment to humans, in some ways as forbidding and remote as the void of outer space.

Although researchers have taken samples of deep-ocean rocks and sediments for over a century, the first detailed global investigation of the ocean bottom did not actually start until 1968, with the beginning of the National Science Foundation’s Deep Sea Drilling Project (DSDP). Using techniques first developed for the offshore oil and gas industry, the DSDP’s drill ship, the Glomar Challenger, was able to maintain a steady position on the ocean’s surface and drill in very deep waters, extracting samples of sediments and rock from the ocean floor. The Glomar Challenger completed 96 voyages in a 15-year research program that ended in November 1983. During this time, the vessel logged 600,000 kilometers and took almost 20,000 core samples of seabed sediments and rocks at 624 drilling sites around the world. The Glomar Challenger’s core samples have allowed geologists to reconstruct what the planet looked like hundreds of millions of years ago and to calculate what it will probably look like millions of years in the future. Today, largely on the strength of evidence gathered during the Glomar Challenger’s voyages, nearly all earth scientists agree on the theories of plate tectonics and continental drift that explain many of the geological processes that shape the Earth. The cores of sediment drilled by the Glomar Challenger have also yielded information critical to understanding the world’s past climates. Deep-ocean sediments provide a climatic record stretching back hundreds of millions of years, because they are largely isolated from the mechanical erosion and the intense chemical and biological activity that rapidly destroy much land-based evidence of past climates. This record has already provided insights into the patterns and causes of past climatic change—information that may be used to predict future climates.

The Deep Sea Drilling Project was significant because it was ().

A. an attempt to find new sources of oil and gas

B. the first extensive exploration of the ocean bottom

C. composed of geologists from all over the world

D. funded entirely by the gas and oil industry