Dear Mr.Smith It was a pleasure having you teach us English Speech last term. I am writing to invite you to be a judge for the upcoming English speech contest. You have more experience in English speech than the other teachers. The enthusiasm and extra effort that you make to engage with your students really helps them to improve. Being a judge would require giving comments and advice to the participants. The competition will be held at the Center of Students' Activities, at 18:00, on December 21. I look forward to your participation and I am convinced that, with your support, the contest will be a success. Please reply at your earliest convenience. Yours sincerely, Li Ming

Jordan is right for sentence 1. Sentence 2. - Do you mean 'The magic has changed the monkey back into what it was in the movie' ? Still sounds awkward. What's the rest of the paragraph?

'rise to a challenge' just means to increase you're effort and ability to overcome a challenge. If you 'meet a challenge', it means you succeeded. As in 'I met the challenge to climb Everest'.

Young and old share a lack of responsibilities!

Most teenagers have some smart digital vocabulary around web pages, games, social media etc. You can try discussing emojis and what they represent.

'..up here..' can mean 'further along in the direction you are travelling', as in 'keep going up here for 5 minutes then turn right'. or if you're walking along a path in a forest - 'let's explore up here and see what we find.'

No. Instead you could say: "I'll be there at the right time" Due means the time at which something is expected to happen: "When is the train due?" (what time is the train expected to arrive?); or to a pregnant woman - "When are you due?" ('to have the baby' is assumed here).