It is the summer vacation now, and we are actively contributing to the infrastructure development of this city, adding bricks and mortar to its growth. Of course, that's just figurative language; in plain terms, it means doing manual labor.,When Wang Ming suddenly saw him walking over, he stopped short. His hands instinctively tightened on his school bag strap, appearing somewhat nervous and afraid.,But Wang Ming was used to wandering and naturally prepared these things.。