It’s not firsthand information.那不是第一手资料。I learned the news about her mother's illness firsthand from Lena.我直接从丽娜那里了解到她母亲生病的消息.School trips give children firsthand experience not available in the classroom.学校组织的出游能让孩...
他们沿校墙挖沟.They dug a dike along walls of the school.挖沟以排水.Dig trenches to drain away the water.他们挖沟以阻止森林大火蔓延.They dug trenches to keep the forest fire from spreading....