If the buoyant force on a ship’s hull is equal to the displacement tonnage, the ship cause（）.

A . tape face B . tapered face C . surface D . thinner face

A . require ballast B . be down by the head C . sink D . float

A . sysdumpdev -k  B . sysdumpdev -L  C . sysdumpdev -K  D . sysdumpdev -P

A . a low load on the unit B . a clogged pump suction strainer C . a blockage in the line between the pump and hydraulic motor D . the hydraulic motor turning too fast

A . heel until the angle of loll is reached B . list until the center of buoyancy is aligned vertically with the center of gravity C . trim to the side opposite TCG until all moments are equal D . decrease draft at the center of flotatio

A . turning to port B . turning to starboard C . decreasing speed D . increasing speed

A . be jammed B . be opened C . be seated D . be broke

A . back current from the rudder B . greater pressure on the right or left side of the propeller，depending on rotation C . lower pressure on the right or left side of the propeller，depending on rotation D . torque from the velocity and angle at which the surrounding water impinges upon the propeller blade

A . only when there is positive stability B . only when there is negative stability C . only when there is neutral stability D . at all time

A .  sysdumpdev -k  B .  sysdumpdev -L  C .  sysdumpdev -K  D .  sysdumpdev -P

A . only when there is positive stability B . only when there is negative stability C . only when there is neutral stability D . at all time

A .  Boolean exists=Directory.exists （“prefs”）； B .  Boolean exists=（new File（“prefs”））.isDir（）； C .  Boolean exists=（new Directory（“prefs”））.exists（）； D .  Boolean exists=（new File（“prefs”））.isDirectory（）； E .  Boolean exists=true；  Try{  Directory d = new Directory（“prefs”）；  } catch （FileNotFoundException e） {  exists = false；  }

A . reset of the primary supervisor B . manual switchover from standby to active supervisor C . manual switchover from active to standby supervisor D . automatic switchover from active to standby on primary supervisor failure

A . liquid in the cylinder B . low compression in the cylinder C . high exhaust temperature D . poor fuel penetratio

A . One ring life buoy B . One ring life buoy on each side of the ship C . Three ring life buoys D . Two ring life buoys on each side of the shi

A . center of gravity B . center of flotation C . metacenter D . metacentric height

If something is'- on the tip of the tongue" (Paragraph 4) , _ ' [A]you say it in a polite way [B] you remember it all your life [C] you don' t want to write it down [D] you know it but can ' t remember it

As the mountains sank, ocean water charged over the lowest arts of the remaining land, forming a series of twisting inlets and lagoons (咸水湖) . The highest parts of the former mountain range, nearest the shore, remained as islands. ______【47】Marine fossils found here were 225 feet above sea level, indicating the level of the shoreline prior to the glacier. The 2, 500-mile-long rocky coastline of Maine keeps watch over nearly two thousand islands. Many of these islands are tiny and uninhabited, but many are home to thriving communities. Mt. Desert Island is one of the largest, most beautiful of the Maine coast islands. Measuring 16 miles by 12 miles, Mt. Desert Island was essentially formed as two distinct islands. ______【48】. For years, Mt. Desert Island, particularly its major settlement, Bar Harbor, afforded summer homes for the wealthy. Recently though, Bar Harbor has become a rapidly growing arts community as well. But the best part of the island is the unspoiled forest land known as Acadia National Park. Because the island sits on the boundary line between the temperate (温带) and sub-Arctic zones, the island supports the plants and animals of both zones as well as beach, inland , and alpine (高山 的) plants. ______【49】The establishment of Acadia National Park in 1916 means that this natural reserve will be perpetually available to all people, not just the wealthy. Visitors to Acadia may receive nature instruction from the park naturalists as well as enjoy camping, cycling, and boating. Or they may choose to spend time at the archeological museum, learning about the Stone Age inhabitants of the island. The best view on Mt. Desert Island is from the top of Cadillac Mountain. ______【50】. From the summit, you can gaze back toward the mainland or out over the Atlantic Ocean and contemplate the beauty created by a retreating glacier. A. It also lies in a major bird migration lane and is a resting spot for many birds. B. Mt. Desert Island is one of the most famous of all of the islands left behind by the glacier. C. The wealthy residences of Mt. Desert Island selfishly keep it to themselves. D. The term comes from the activity of the Ice Age. E. This mountain rises 1, 532 feet, making it the highest mountain on the Atlantic seashore. F. It is split almost in half by Somes Sound, a deep and narrow stretch of water seven miles long. (46)

A．an external force, translation, an external couple moment, rotation B．an internal force, translation, an internal couple moment, rotation C．an internal force, movement, a couple moment, translation D．an external force, translation, an internal couple moment, translation