【题目】The main problem with the road is ________the road conditions need________.
A．that; to be improved
B．which; to be improved
C．where; improving
D．when; improving
在线课程【答案】A
【解析】由句子结构可知，从句中不缺成分，这是一个同位语从句，说明名词problem，意思是“问题就是路的质量需要提高”。conditions与improve之间为被动关系，故用doing或to be done即可。