_______ a reply, he decided to write again.[ ]

A. Not receiving  

B. Receiving not    

C. Not having received    

D. Having not received

教师职业是复杂而富有创造性的职业，从事这一职业的人必须（）。

A.富有耐心

B.固步自封

C.富有深厚

D.老练持重