When the precast pile is hit by hammer, the correct method for selecting the pile hammer is （）.

A、On the chart B、Coast Pilot C、Light List D、Notice to Mariners

A . Twice the dry bulb temperature B . 10℃ above the dry bulb temperature C . 5℃ above the dry bulb temperature D . Equal to the dry bulb temperature

A . temperature of the air equals the temperature of the seawater B . atmospheric pressure is 14.7 lbs. per square inch C . relative humidity reaches 50% D . air becomes saturated with water vapor

A . dike B . revetment C . cutoff D . cri

A . keep all systems in normally running B . the main engine is stand-by C . shut off the starting air bottle outlet valve D . pay attention to the changes of the system parameter

A . lower than B . higher than C . as much as D . the same a

A . the inlet valve is open B . the exhaust valve is open C . both valves are close D . both valves are ope

A . A gatekeeper is contacted to determine the correct local gateway to use. B . A gateway will receive the call and forward a call request to the local gatekeeper. C . A gateway will receive the call and forward a call request to the gatekeeper on the other side of the WAN D . A gatekeeper will receive the call and forward a call request to the remote gateway.

A . When the value of MAX_CONNECTIONS is greater than the value of MAX_COORDAGENTS.   B . When the value of MAX_AGENTS is greater than the value of MAX_CLIENTS.   C . When the value of NUM_AGENTS is greater than the value of MAX_AGENTS.  D . When the value of NUM_CONNECTIONS is greater than the value of NUM_COORDAGENTS.

A . GM B . free surface C . longitudinal center of gravity D . transverse center of gravity

A . deteriorate and give off noxious gasses B . spontaneously heat and catch fire C . attract lice and other vermin and serve as a breeding ground D . None of the above

A、 unchanged B、 decreased C、 eliminated D、 increased

A . change from diesel oil to heavy fuel oil for mail engine B . pump out bilge water C . change sea chest form lower level one to high level one D . test emergency generator

A . taut and leading forward B . slack C . leading out perpendicular to the centerline D . leading under the hull

A . After stopping supplying sludge oil, the value and pipe should be flushed by flushed by diesel oil and the incinerator continue burning for 10 minutes B . Close auxiliary burner firstly and then close main burner C . After stopping fuel, restoring the position of main fuel supply valve D . Stop blower as soon as stopping supplying fuel oil

A．November 9th, 2009 B．November 3rd, 2009 C．November 14th, 2009 D．November 15th, 2009

<img src='https://img2.soutiyun.com/shangxueba/ask/64242001-64245000/64243546/1f468ca01a2e34dcaae3710fa02b98c8.jpg' /> A.00 B.0001 C.000120 D.00012021 E.Compilation fails. F.An exception is thrown at runtime.

A．March 18 B．March 29 C．April 1 D．April 16

A．June 7. B．June 15. C．June 21. D．June 16.

The puzzle had to do with waves. Though it might seem intuitive that waves carry water to shore, and sand along with it, it's not that simple. The crest(浪尖)of a passing wave lifts a given hit of water upward and landward, but the ensuing trough(波谷) pushes the water back down and Out to sea. Near the bottom, there the sand is, the water was always assumed to just slide back and forth—and the sand with it. "If you take a very aloof look at a beach," says Inman, "you'll realize that if the two motions move sand back and forth the same amount, then all the sand should end up in deep water.' So for beaches to exist, the crest's onshore flow must somehow move enough sand up the beach to counter the seaward tug of both the trough and gravity . The pressure changes in the sand bed, Inman and Conley think, are the key to beach creation. They found that sand doesn't just slide back and forth with each passing wave. Under a trough, it does slide seaward, in a thin layer just above the bottom. But under a crest its movement is often more elaborate. The higher pressure under a crest—higher because the water is piled higher—forces water into the porous(多孔的) sand. This creates strong whirlpools just above the sand, which help loosen it. As the crest passes overhead, the sand first rushes across the bottom; then it abruptly turns violent lifting off the bottom in large, boiling bunches. Finally, just after the crest passes, the sand explodes up into the great water column. The boiling and rushing move more sand than the backsliding under a trough, so there's a net movement of sand toward the shore. What is the primary purpose of this passage？ A．To explain why sand piles up on the beaches. B．To explain why men only prostrate in the sea. C．To propose a new explanation of a phenomenon. D．To refute a misconception.