Dear Sir / Madam,
I thank you for your kind words and the assignment you have given me for upcoming summer position.
While I appreciate the opportunity to learn from work, knowing it is a respective assignment, I also would like to know if it's possible to experience other job categories such as cashier, sales rep or kitchen staff etc, so that I can fully utilize every chance to experience the culture, be a team player and improve my English conversation ability.
At last, I thank you for your time and consideration, look forward to hearing from you soon.
OK, if I am not mistaken, you are a college student, why are you taking this kind of summer job in the US ? You know, majority of janitors here in the States are illegal immigrates or those who don't speak English but Spanish. Are you taking L VISA coming like the other person ?
Be careful, don't get fooled / cheated by human smuggler ring.
Live in the US...