We planted these trees last year.怎么改成被动句,求答案

We planted these trees last year.怎么改成被动句,求答案 These trees were planted last year.变成否定句They weren't planted last year.为什么these trees 要用they So far we ( ) about 1000 trees. a.planted b.have planted c.have been planted d.to plant说明原因 by the time he showed up ,we （）ten trees A have planted B had planted Many trees ___(plant) in our school yard these years.1.have been planted 2.are planted选哪个?为什么? mang trees have been planted by people themang trees have been planted by people these years改主动语态 We planted trees last weekend改为特殊疑问句 We planted many flowers in the neighborhood改为被动语态 trees in many we the planted park连词成句 We planted many trees on the hill变成被动语态 We on the farm and watered planted trees 什么意思 There __(be)a telephone call for you five mintues ago如题..填空写什么?These trees in our school ________ten years oldA.were planted B.are planted C.planted D.was planted twenty trees had been planted by the time we left为什么要用had been planted 这个时态而不是had planted It's spring now,the students ()trees these weeks为什么是are planting而不是planted We have planted over 1000 trees.We'll plate__(many)trees next yearShe was__at the___end(amaze) Solo tre Tre 是什么意思 tre丶霜