Dear li ming：
I've heard of you are intend to take a trip with your classmates.Of course it will be a nice journey for all of you if you can make some preperations before leaving.Here are some tips I think may be helpful.
First of all,some OTC drug should be put into your luggage.No doubted some unexpected situations may cause injury and in case of you cannot take timely response measures,What's more,cash shouldn't prepared too much which may cause some unnecessary unsafety.Last but not least,makeing telephone calls to yours parents everyday is important.You know we all care about you and to comfort us you have the duty to tell us how things stand.
I know tips are quite wordy .So enjoy your tour and have a good time~!
your sincerely
John