碾碎了的，磨过的，磨成粉的。 ground and polished piston 【机械工程】研磨活塞。
- the first or preliminary coat of paint or size applied to a surface
同义词：flat coat, primer, priming, primer coat, priming coat, undercoat
- (art) the surface (as a wall or canvas) prepared to take the paint for a painting
- a connection between an electrical device and a large conducting body, such as the earth (which is taken to be at zero voltage)
- a relatively homogeneous percept extending back of the figure on which attention is focused
- the part of a scene (or picture) that lies behind objects in the foreground; "he posed her against a background of rolling hills"
- a position to be won or defended in battle (or as if in battle); "they gained ground step by step"; "they fought to regain the lost ground"
- a rational motive for a belief or action; "the reason that war was declared"; "the grounds for their declaration"
- the solid part of the earth''s surface; "the plane turned away from the sea and moved back over land"; "the earth shook for several minutes"; "he dropped the logs on the ground"
同义词：land, dry land, earth, solid ground, terra firma
- material in the top layer of the surface of the earth in which plants can grow (especially with reference to its quality or use); "the land had never been plowed"; "good agricultural soil"
- a relation that provides the foundation for something; "they were on a friendly footing"; "he worked on an interim basis"
- the loose soft material that makes up a large part of the land surface; "they dug into the earth outside the church"
- use as a basis for; found on; "base a claim on some observation"
同义词：establish, base, found
- instruct someone in the fundamentals of a subject
- connect to a ground; "ground the electrical connections for safety reasons"
- fix firmly and stably; "anchor the lamppost in concrete"
- cover with a primer; apply a primer to
- hit onto the ground
- hit a groundball; "he grounded to the second baseman"
- throw to the ground in order to stop play and avoid being tackled behind the line of scrimmage
- place or put on the ground
- confine or restrict to the ground; "After the accident, they grounded the plane and the pilot"
- hit or reach the ground
- bring to the ground; "the storm grounded the ship"
同义词：strand, run aground