【题目】He failed his maths examinations ________his careless work
A. because of B. because
C. thanks for D. as a result
在线课程【答案】A
【解析】
考查固定短语辨析。句意：因为他粗心的行为，他数学考试不及格。A. because of因为； B. because因为；C. thanks for多亏；D. as a result结果，because of接成分，because后面接句子，故选A。