问题
选择题
He was fired ____his carelessness and laziness.
A．because of
B．because
C．thanks to
D．since
答案
答案：A
首先根据后边的名词carelessness和laziness排除B、D选项（because和since表原因时用作连词，引导原因状语从句）；because of表原因意为“因为，由于”，thanks to意为“多亏了，幸亏……”，故答案选A。