get-\-\-got give-\-\-gave have-\-\-had make-\-\-made put-\-\-put read-\-\-read throw-\-\-threw 一、写出下列动词的过去式或动词原形。 1.go___ 2.is___ 3.buy___ 4.swim___ 5.have ___ 6. watch...
2.时间状语:recently, lately, since…for…,in the past few years, etc. 3.基本结构:have/has + done 4.否定形式:have/has + not + done. 5.一般疑问句:have或has提前。 6.例句:I've written an article. It has been raining these days. 六、过去完成时 1.概念:以...
18.our products have been sold in a number of areas abroad. 我们的产品行销海外许多地区。 19.It's our principle in business to honor the contract and keep our promise. "重合...
have(has) gone to,have(has) been to和have(has) been in的区别 1. have (has) gone to表示"已经去某地了",不能与for+一段时间连用。 She has gone to Shanghai.(她可能已在去上海的路...
But now, places have been found on earth that are in total blackness such as caves several miles beneath the ocean. And bacteria, primitive forms of life, have been seen there。意为科学家一直以为光是很重要的,但是现在他们发现完全黑暗的地方—比如几英...
更多内容请点击：小学英语必须掌握的4大时态讲解(附专项练习和答案)