最小的非零自然数是最小的一位纯小数的______倍．

Soon, more of the information we receive via the Internet could come (155) in digital wrappers.
Wrappers are made up, (156) software code that’s targeted to do specific things with the data (157) within them, such as helping to define queries for search engines. They also keep (158) from (159) access to that code.

A．close

B．closed

C．enclose

D．enclosed