题目

People are being tricked into Facebook with the promise of a fun, free service without realizing they’re paying for it by giving up loads of personal information. Most Facebook users don’t realize this is happening. Even if they know what the company is up to, they still have no idea what they’re paying for Facebook because people don’t really know what their personal data is worth. The biggest problem, however, is that the company keeps changing the rules early on you keep everything private. That was the great thing about Facebook. You could create your own little private ne 第五次全国人口普查结果显示，我国的总人口已达到1 300 000 000人，用科学记数法表示这个数，正确的是 [　　] A．1.3×108 B．1.3×109 C．0.13×1010 D．13×109