(2013·南京二模)—What do you think of the news in today's newspaper?—We shouldn't ________ the trouble of helping others only because what we do may invite trouble.

The tourist attraction is so designed to________our local customs and cultures in some aspects.

 I invited Joe and Linda to dinner，but ________ of them came.

After great efforts President Obama was elected to a second＿＿＿ of office

 Frequently, single—parent children       some of the function that the absent adult in the house would have served .