第(13)和(14)题基于以下的5阶B树结构，该B树现在的层数为2。

往该B树中插入关键码72后，该B树的第2层的结点数为

A．6

B．7

C．8

D．9

It takes a long time to _____ a good name, but this name is quickly lost by just one piece of bad behavior.

A．pick up

B．think up

C．build up

D．make up