参考答案暂无解析:
opposite。本题的出题点在并列句式处(and)。讲座中提到This is usually described as giving out double messages--one message in words and an opposite message in body language．即：我们的口头语言和身体语言经常暗含不同含义的信息——口语发出一种信息，而身体语言却发出与此相反的信息，故得答案opposite。
A．Some people don't want to take it because it's too time-consuming． B．The results might not be objective enough． C．The survey aims to measure Americans' happiness． D．The survey has been conducted for three months．