简述乙烯原料的主要来源。
参考答案：原料主要来源于原油直接蒸馏，馏分油二次加工，以及天然气和油田气等。
根据句意及所给首字母，完成单词。
1．Our teachers are having a m ________ in the teachers' office.
2．Can I b ________ your bike? Mine is broken.
3．Lucy h ________ traveling by plane, but she likes taking the train.
4．Thank you very much for i ________ me to your party.
5．Please don't play w ______ that dog. It's dirty.
以下属于自动识别输入技术的有（）
A.条形码技术
B.磁条（卡）技术
C..声音识别技术
D.视觉识别技术
E.智能卡
