._________,the building gave us a deep impression.

A．Designing beautifully

B．Beautifully designed

C．Design beautifully

D．Beautifully designing

一把钥匙只能开一把锁，现在有4把钥匙4把锁，但不知哪把钥匙开哪把锁，最多要试多少次就能配好全部的钥匙和锁( )

A．6

B．8

C．7

D．5