题目

阅读短文内容，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。Canberra is thecapital of Australia. Theincreasing speed of popularity is the fastest in Australia. Canberra is the eighthlargest city in Australia. It is 238 kilometers from Sydney and 507 kilometersfrom Melbourne. Melbourne was once the capital of Australia. Sydney people alsowished to make their city capital. It was difficult for the government to makethe decision. The new capital wasbetween Sydney and Melbourne, the two largest cities in Australia. It took morethan 12 在下列多项式中加上适当的项，使多项式成为一个完全平方式： (1)9x2－6x；(2)25x2＋30x．