Yesterday was Tree Planting Day. The teachers asked us to plant trees at the corner of our playground. At 3:00 in the afternoon,we got there. Our teacher showed us how to plant trees. Then we started to do it. Some dug holes,some put the young trees into the holes and others watered them. We worked very hard. We planted 50 trees. When we finished our work,it got dark (黑暗的). But we were all happy because it made our school more beautiful.
根据短文内容,回答下列问题。A.were | B.are | C.did |