_____ the earth to be flat, many feared that Columbus would fall off the edge of the earth. [ ]

A. Having believed

B. Believing

C. Believed

D. Being believed

（）经两次有效投递未能投出的，改为局内投交。

A.个人包裹

B.单位包裹

C.单位地址的包裹

D.特快专递邮件