选择并使用所给英语单词的正确形式完成句子，有两个单词为多余词。

channel   boundary   choke   purchase   priority   advertise   faith

【小题1】Her voice was ________ with excitement when her dream star smiled at her.
【小题2】If you want to attract more customers, try ________ on the Internet.
【小题3】Nowadays, ________ of communication have made it possible to speak instantly with someone on the other side of the planet.
【小题4】There are a couple of things you should put on your list of ________.
【小题5】Scientists continue to push back the ________ of human knowledge.