1.着急:feel anxious 担心:worry sb/sth.
2.完: we often use “verb+完” means something have done. And “完“also can be used means “be sunk / go to the dogs /died (when you are kidding) “ can’t change to “结束“。And if use this word as “end” it means something finished according to the plan.
“结束“is When you mean something stop and finished use focus on that will not continue.
3.At here. I think maybe you find 2 word“join” in English. But it’s exactly different. “接”often means “connect sth. Combine something together “ and “接+sb”means “pick sb up”
“参加”means “attendant , take part in sth”
4.愿意~I’d like to ~
希望 ~ I hope ~