已知函数f(x)=2^x+3，f^-1(x)是f(x)的反函数，若mn=16(m,n$\in R^{+}$），则f^-1(m)+f^-1(n)的值为     （   ）

小明把自己一周的支出情况，用右图所示的统计图来表示，下面说法正确的是（     ）

阅读下面短文，掌握其大意，然后从每小题所给的A、B、C、D四个选项中，选出一个最佳选项。

    School education is very important and useful. Yet no one can  1  everything at school and a teacher can't teach his students everything they want to know. His 2  is to show his students how to learn. He teaches them how to read 3 how to think. So much more is to be learnt outside school by the students 4.

     It is always more  5 to know how to study by oneself. It is quite  6  to learn something, but it is difficult to use it to solve problems. Great inventors (发明家) don't get everything  7  school, but they still can 8 many things and change the world a lot.

     How can the inventors do all of these? One of the answers is: they   9  how to study. A lot of things are not learnt in the classroom. They get a lot of knowledge by reading outside school. They work hard and never  10  their dreams.