Before revision:  In this paper, we propose a novel cause-effect look at the language bias , where the bias is formulated as the direct  effect of question on answer from the view of causal inference.
After revision:  In this paper, we propose a novel cause-effect look at the language bias , where the bias is formulated as the direct causal effect of questions on answers and reduce the language bias by subtracting the direct language effect from the total causal effect of question on answer from the view of causal inference.