试题题干
WORD FORMATION
Complete each of the following sentences with the proper form of the word in brackets.
Private cars are assumed to have 
our horizons and increased our mobility. (wide)
参考答案
试题解析
此处缺少动词过去分词。
have+动词过去分词构成现在完成时。所以变wide为动词widen，然后再变为过去分词widened。词组wide one‘s horizons，意思是开阔某人眼界。
句意：私家车被认为拓宽了我们的视野，增加了我们的机动性。