【正确答案】 D

【答案解析】[理由] 本句测试下列连接词的意思：
(A) and 而且
[例] He is handsome, and he is rich.
(他人长得帅又有钱。)
(B) so 因此
[例] He is nice, so I like him very much.
(他人很好，所以我很喜欢他。)
(C)but 但是
[例] He is nice, but I don't like him.
(他人很好，但我不喜欢他。)
(D) Or 否则
[例] You should keep working hard, or (else) you'll achieve nothing.
(你应该继续努力，否则将一事无成。)
根据语意，空格内应置or(否则)，因此(D)应为正选。