– Do you know why the river was polluted
题型：选择题
问题：
– Do you know why the river was polluted?
-- Many different factors ___________ the serious pollution of the river.
A．contributed to
B．adjusted to
C．were accustomed to
D．were attached to
– Do you know why the river was polluted?
-- Many different factors ___________ the serious pollution of the river.
A．contributed to
B．adjusted to
C．were accustomed to
D．were attached to