单项选择题
A team of researchers ______ the problem of diseases connected with contaminated milk.
单项选择题 He implied that the President had lied and ______ obstructed justice.
单项选择题 The teacher wanted to make the students realize that reading good literature is a good way to broaden their ______.
单项选择题 They did not realize that they had ______ a crime by cutting down the tree.
