Sales went down ________ difficult trading conditions.

Sales went down ________ difficult trading conditions.
A、because　
B、thanks to　
C、since　
D、due to
【正确答案】：D
【题目解析】：because意为”因为“，其后接句子；thanks to意为”多亏“；since意为”自从......以后“；due to意为”由于“。句意：由于贸易条件不好，销售额下降了。