Nobody yet knows how long and how seriously the shakiness in the

Nobody yet knows how long and how seriously the shakiness in the financial system will （） down the economy.
A、put
B、settle
C、drag
D、knock
【正确答案】：C
【题目解析】：此题考查有关down的搭配。put down放下，镇压；settle down，定居，安心于；drag down拖垮；knock down击倒，拆卸。本题句意为：无人知晓这次经济体系的变动会在多长时间内，多大程度上使经济濒临崩溃的边缘。因此选C，拖垮经济。