my teacher didn't tell me directly, I still felt that I didn't live up to her expectation.
A. When
B. Since
C. As
D. While
网友回答
A. When
B. Since
C. As
(答案→)D. While
解析：D考察连词。句义：虽然老师没有直接告诉我，但是我仍然感觉到辜负了她的期望。While在本句中作为连词，意为：虽然；when既然，当…时；since因为，由于；as因为，随着；根据语境可知D正确。