1．Recently，a new research has suggested the possibility in a popular magazine pleasant smells might reduce pain.
that 解析：句意：最近，在一本流行杂志中，有一项新的研究表明好闻的气味有可能减少疼痛。设空处引导同位语从句，对possibility进行解释说明，且从句中不缺成分，意义完整，故填that。
2．You should first explore your talents and get to know yourself so as to make a list of you think your real interest lies.
where 解析：句意：你应当首先开发你的天赋，了解你自己，以便列出一个你认为你真正的兴趣所在的单子。设空处引导宾语从句，作介词of的宾语，且在从句中作地点状语。
3．Through the process of comparison, it might be easier for us to understand important belief really is.
how 解析：句意：通过比较的过程，我们可能更容易理解信念是多么重要。设空处引导的从句作understand的宾语，且修饰形容词important，应用how引导该从句。
4．With an optimistic attitude and a strong will, we can overcome difficulties we might meet with and achieve our goals.
whatever 解析：句意：拥有乐观的态度和强烈的愿望，我们能够克服可能遇到的任何困难，取得成功。通过分析句子可知，overcome后为宾语从句，动词短语meet with后缺少宾语，再结合句意可知用whatever修饰名词difficulties，引导宾语从句。
