Eventually, I just get rid of my curiosity about Google TOS that I never read since I started using Google's services for almost 5 years.
I found something interesting in item 2.3 of Google TOS, that is:
2.3 You may not use the Services and may not accept the Terms if (a) you are not of legal age to form a binding contract with Google, or (b) you are a person barred from receiving the Services under the laws of the United States or other countries including the country in which you are resident or from which you use the Services.
Well, this item could be used to againts those who are underage use Google to do something that is disallowed at their age. But, seems like nobody cares about it. Google is freely used at any age here. Fortunately, I am old enough to use Google. 
By the way, if you have Google Chrome, why don't you type on your Omnibox: about:terms, and see the same TOS.
I think I shouldn't suggest to anyone (who is underage) to use Google Chrome (just in case of getting arrested, LOL). Oh ya, Firefox, Opera, and IE7 too, they has inbuilt search engine location to Google. Hmm... IE6? 