题目内容：

Helen made many mistakes in the maths test She realised that ___important to be careful.A was it B was there C it was D there was 要说明

优质解答

选C 首先排除AB,因为that后面是一个陈述语气的从句.其次排除D,因为这里it是形式主语,不须翻译出来,意思是“考试认真是很重要的”.D There be句型表示“有”,用在这里显然是错误的