十萬火急....

I think it’s mobile phone.

personal reasons:
1. I don’t like phoning people, it costs me a lot of money

2. It’s troublesome when people calling me continuously, but I can’t easily tell them I am not at home =____=

3. Computer can do many more things than mobile phone. I can contact friends by computer too. Also, using notebook can be as convenient as mobile phone.

4. money is my life, I can’t buy or do a lot of things without it. Cash gift is different from the usual pocket money, it’s more and helpful, help my shopping.

Among "red packets", "mobile phone" and "computer", I will choose "red packets" of the least important item. My friends's phone numbers and the information in the computer are both invaluable and not purchasable.