Often you know from experience how long it takes you to write a short essay,to study for a quiz,
问题描述：
Often you know from experience how long it takes you to write a short essay,to study for a quiz,
or to review for a final exam.请问Often you know from experience和how long it takes you to write a short essay,to study for a quiz,or to review for a final exam.意思是:通常你从经验中知道 多长时间写一短文,准备一个测验,复习期末考试.
答
不是分开的.这个句子因为是often在句子开头,所以应该采用倒装.Often do you know from experience how long it takes you to write a short essay, to study for a quiz,or to review for a final exam.