第27题: [单项选择]The researchers have conducted an experiment to prove that people. will act in emergencies when_____. A. they are in pairs B. they are in groups C. they are alone D. they are with their friends 参考答案:C 答案解析:文中提到的试验证明,当人独自一人时,最可能帮助处于紧急状况下的他人,选C。