1 . At the sight of the birthday gift, a smile ___________ (出现) on her face. (根据汉语提示单词拼写)

2 . With the information explosion in science and technology, more and more new concepts will e______ and need to be defined.(根据首字母单词拼写)

3 . No new evidence ________________ (appear and come out into view)during the investigation last week. （根据英文释义单词拼写）

4 . In years to come, we hope more girl students interested in science and engineering ______(emerge). (所给词的适当形式填空)