问题补充:
The civil war broke out in Libya, to the instability of the international oil price.
A. to contribute
B. contributed
C. having contributed
D. contributing
答案:
A. to contribute
B. contributed
C. having contributed
(答案→)D. contributing
解析:本题考查非谓语动词。contributing to the instability of the international oil price,现在分词在句中作结果状语。选D。