在我国，包装垃圾回收总体情况不乐观，除啤酒瓶和塑料周转箱回收情况较好外，其它包装废弃物的回收率相当低，还不到（）。

A、30%

B、20%

C、10%

D、35%

To have a computer without being connected to the Web is like having an old radio when everybody else has a color TV. That helps explain ______ businesses are setting up Net sites even though profits are nowhere to see.

A．reasons

B．the reason for

C．why

D．why that