根据短文内容，从方框中选择恰当的单词完成句子。部分单词在填入前需进行词形转换，每个单词只能用一次，每空只能填一词。

    It's very important to know something about traditional presents. In the West, people often take flowers when they  others. Different flowers have different . For example, people often give red roses to  who they love. In Greece, you must not give white flowers because white flowers are for the . When you go to a foreign country, it is always best to check what people do. If you remember this, you can avoid making a lot of mistakes.