wheel
crankshaft
running gear
cam
第1题：
Evaluate this SQL statement: SELECT e.EMPLOYEE_ID,e.LAST_NAME,e.DEPARTMENT_ID, d.DEPARTMENT_NAME FROM EMP e, DEPARTMENT d WHERE e.DEPARTMENT_ID = d.DEPARTMENT_ID; In the statement, which capabilities of a SELECT statement are performed?（）
A. Selection, projection, join
B. Difference, projection, join
C. Selection, intersection, join
D. Intersection, projection, join
E. Difference, projection, product
第2题：
Which of the following statements represents an advantage of an electromagnetic clutch?
A.Large misalignments can be tolerated between the shaft and engine coupling
B.Slip is held to a minimum when reversing shaft rotation
C.Engine torsional vibrations to the driven shaft are eliminated
D.It aids in maintaining power factor
第3题：
[A] objection [B] projection [C] project [D] object
第4题：
A wobbling tail shaft is an indication of ______.
A.shallow water
B.an engine that is misfiring
C.a tight tail shaft gland
D.worn stern bearing or misalignment
第5题：
______is a rounded projection at the forward end of a ship which reduces water resistance，thus allowing an increase in speed when the ships is in ballast．
A.Bulbous bow
B.Ellipse bow
C.Cyclical projection
D.Gnomonic projection
第6题：
A. Selection, projection, join
B. Difference, projection, join
C. Selection, intersection, join
D. Intersection, projection, join
E. Difference, projection, product
第7题：
What prevents water running along the shaft of a leaking centrifugal pump from entering the shaft bearing ________．
A.Shaft seal
B.Water flinger
C.Drain hole
D.Lantern ring
第8题：
A SELECT statement can be used to perform these three functions:1. Choose rows from a table.2. Choose columns from a table3. Bring together data that is stored in different tables by creating a link between them. Which set of keywords describes these capabilities? （）
A. difference, projection, join
B. selection, projection, join
C. selection, intersection, join
D. intersection, projection, join
E. difference, projection, product
第9题：
A chart projection depicting the poles and a small area on either side of a connecting meridian, that is sometimes used for star charts, is the ______.
A.azimuthal gnomonic projection
B.Lambert conformal projection
C.transverse Mercator projection
D.polyconic projection
第10题：
Main shaft