A：31.4
B：109.9
C：62.8
下列各句中划线的成语使用恰当的一项是（ ）
Nowadays, more and more students choose to take a gap year. That is, they take a year ____ between the ending of high school and the beginning of university.
鸟类和哺乳类是由哪一种动物进化而来的？（ ）
