Three fourths of the earth’s surface_______ water.地球表面四分之三是水。

______ is covered with heavy snow. A: The surface of earth B: The earth’s surface C: The earths’ surface D: The surface

_____ is covered with heavy snow. A: The earth’s surface B: The surface of earth C: The surface earth D: The earth surface

What is the name of the solid surface in the figure below?[img=360x664]1803bb9e6fc6d99.jpg[/img] A: circular cone surface B: Cone-shaped surface C: Cylindrical surface D: Columnar surface

For soft tooth surface gear transmission, the hardness of the tooth surface should be selected A: Pinion tooth surface hardnesslarge gear tooth surface hardness B: Pinion tooth surface hardness≤large gear tooth surface hardness

The principles for machining sequence of each surface should be( )<br/>and perform rough machining before finish machining. A: perform datum surface machining before that of other surfaces B: perform main functional surface machining before less important surface machining C: perform plane surface machining before hole surface machining D: perform complex surface machining before simple surface machining

把两个曲面进行连接曲面的命令是？ A: attach surface B: detach surface C: rebuild surface D: open\close surface

抛光表面直到非常光泽。 A: Polish the surface until it is very shiny. B: Polish the surface until it gleams. C: Polish the surface to a high gloss.

The effects of free surface on initial stability depend upon the dimensions of the surface of the free liquids and the（）.

Where is the measuring position of the uneven gauge in our country？ A: 10mm below the rail top surface B: 12mm below the rail top surface C: 14mm below the rail top surface D: 16mm below the rail top surface