Ⅰ.单词拼写
根据汉语或首字母提示，写出下列单词
1．I must apologise(道歉) for not being able to meet you.
2．The basic causes are unknown(未知的)，although certain conditions that may lead to cancer have been discovered.
3．(2019·全国卷Ⅲ，阅读七选五)Participate in discussion forums(论坛)，blogs and other openended forums for dialogue.
4．His heroic deeds(行为) were celebrated in every corner of India.
5．Within this lecture(演讲) I cannot pretend to deal adequately with dreams.
