四六级考试

【单选题】Agriculture is undoubtedly the most important sector in the economies of most non-oil exportingAfrican countries. It (62) about 30% ofAfrica’s GDP and contributes (63) 50% of the total export value, (64) 70% of the continent’s population depending on the sector for their (65) . Production is subsistence in nature with a high (66) on the rain. The debate on climate change and its impacts on agriculture is (67) very crucial to the very survival of the continent and its people. The continent is particularly (68) to climate change because it includes some of the world’s poorest nations.
The climate inAfrica is (69) tropical in nature, which is broadly (70) into three main climatic zones: (71) equatorial, dry, and temperate(温带). Within these zones, altitude and other localized (72) also produce distinctive regional climates.
Climate change, (73) indicated by prolonged drought is one of the most serious climatic (74) affecting the agricultural sector of the continent.As most of the agriculture activities inAfrican countries hinges on rain fed, any adverse changes in the climate would likely have a (75) effect on the sector in the region.
(76) changes in the climate may affect the whole continent, its (77) may vary across the continent. In northeastAfrica, more intense dry periods and shorter wet seasons are expected to affect even huge river systems such as theBlue Nile, leading to serious water shortages and (78) consequences to the agriculture and forestry sectors throughout the region.East andCentralAfrica will also see its agricultural (79) decline.Coastal areas may also be affected by rising sea levels and intrusion of salt water into inland freshwater resources. The staple food for the region, maize, is particularly susceptible to drought. Wetlands of international importance and wildlife are also under threat from (80) in SouthernAfric
A、Climate change, therefore, is expected to worsen the food supply, (81) , exacerbate the widespread poverty in the region.

A、and
B．then
C．hence
D．but

网考网参考答案：C
网考网解析：
[一步到位] 逻辑衔接题。本处意思是：气候变化会使食物供应状况恶化，因此加剧贫困。故选C)hence“因此”。 [深度点拨] A)and；B)then；D)but用在此处均不符合逻辑。 document.getElementById("warp").style.display="none"; document.getElementById("content").style.display="block"; 查看试题解析出处>>