短语讲解：

1. Go to the Portable North Pole website and sign up with an email address, Facebook or Google account.

sign up 报名; 跟…签订合同
例句：He was not the only one to sign up.
报名参加的不光是他一个人。

2. Hungry Santa is a game that lets users fill up Santa with sweets and treats.

fill up 填充; 补; （使） 充满
例句：He caught many fish to fill up his belly.
他捉了很多鱼，填饱了肚子。