【题目】Pollution has reachedhigh level in some urban areas, which is quite worrying.
A.disturbingly
B.slightly
C.exactly
D.flexibly

【答案】A
【解析】句意：在一些城市污染已经到了令人不安的程度，这是相当令人担忧的。根据后边which is quite worrying这是相当令人担忧的，可知前边污染已经达到了令人不安的程度。A.disturbingly“令人不安地”；B.slightly“轻微地”；C.exactly“恰好地”；D.flexibly“灵活地”。故选A。