根据短文内容，从短文后的选项中选出能填入空白处的最佳选项。选项中有两项为多余选项。

        My daughter Chloe is starting out in college in the fall. With her newfound independence will come the newfound responsibilities of dealing with money.____Now I have a few lessons I'd like to share with Chloe, and with anyone else starting out in college.

____OK,this is almost the only lesson you need. The biggest reason you get into money problems is that you spend money you don't really have. Then you end up in the hole, and it's hard to get out of the hole. You work too many hours to keep up with your spending. And you end up with a life that's about nothing but trying to pay for all the spending on something you don't really need.____

        Make a very simple budget. It's a terrible thing for people who've never done a budget, but it will become very simple and easy if you know how to do it.____If the bills add up to more than theincome, remove some bills. Pay bills right away. If you have the money, pay thebill as soon as it comes in. You can usually do this online, but if not, it's just a matter of writing a check, putting it in an envelope, and writing out an address—two minutes.____ If you let the bill­ paying get pushed back, it becomes a terrible thing.

      That's all you need to know. If you save when you're in college, avoid debt, and paybills on time, you're golden.

A．Why not enjoy your life in college?

B．Spend less than you earn.

C．So spend less, work less, worry less, be happier.

D．Like many young people, she hates thinking about money.

E．First, list your income, and then list your bills.

F．Find ways to get things done you need to get done.

G．Do this two­minute action at once, so you don't have toworry about it later.

下列各句中，没有语病、语意明确的一项是（     ）

我国的经济体制改革首先是从什么地方开始（     ）

①amol ②bmol ③ $\frac{a}{3}$ mol  ④ $\frac{b}{3}$ mol  ⑤0mol  ⑥（4a﹣b）mol．

小明发现这三种方案都能验证公式：

a²+2ab+b²=（a+b）²，

对于方案一，小明是这样验证的：

a²+ab+ab+b²=a²+2ab+b²=（a+b）²

请你根据方案二，方案三，写出公式的验证过程。