Question

Those countries were once worried that they would not have adequate supplies of petroleum.

A.effective
B.efficient
C.potential
D.sufficient

Answer 1

【答案】：D

本题是对形容词的考查。题干：那些国家曾经担心自己没有足够的原油供应。题干划线词adequate意为“足够的”，effective意为“有效的”， efficient意为“有效率的”，potential意为“潜在的”，sufficient意为“足够的，充足的”，所以正确答案为D。