The secretary read the letter quickly therefore, she did not fin

The secretary read the letter quickly therefore, she did not find all the errors.
【正确答案】：quickly →quickly;
【题目解析】：therefore意为”因此“，前面是一个完整的句子，后面也是一个完整的句子；在英语中可以用分号隔开两个完整的句子。