the global economy is showing signs of recovery many developing countries are still suff

问题补充：

the global economy is showing signs of recovery, many developing countries are still suffering.

A. As

B. Where

C. How

D. While

答案：

A. As

B. Where

C. How

(答案→)D. While

解析：句意：虽然全球的经济有复苏的迹象，许多发展中国家仍然处于困境。表示“虽然”且置于句首的词有：while, although, though。as有“虽然”的意思，但必须用于倒装句。如：child as he is , he knows a lot. 倒装句中除了as，还可以用though。