问题
单项选择题
开工后,承包人必须按照工程师确认的进度计划组织施工,接受工程师对进度的检查和监督。检查和监督的依据—般是双方已经确认的( )。
A.施工进度总计划
B.年进度计划
C.月度进度计划
D.分段进度计划
答案
参考答案:C
开工后,承包人必须按照工程师确认的进度计划组织施工,接受工程师对进度的检查和监督。检查和监督的依据—般是双方已经确认的( )。
A.施工进度总计划
B.年进度计划
C.月度进度计划
D.分段进度计划
参考答案:C
A pilot cannot fly a plane by sight alone. In many conditions, such as flying at night and landing in dense fog, a pilot must use radar, an alternative way of navigating. Since human eyes are not very good at determining speeds of approaching objects, radar can show a pilot how fast nearby planes are moving. The basic principle of radar is exemplified by what happens when one shouts in a cave. The echo of the sounds against the walls helps a person determine the size of the cave. With radar, however, the waves are radio waves instead of sound waves. Radio waves travel at the speed of light, about 300, 000 kilometers in one second. A radar set sends out a short burst of radio waves: Then it receives the echoes produced when the waves bounce off objects. By determining the time it takes for the echoes to return to the radar set, a trained technician can determine the distance between the radar set and other objects. The word "radar," in fact, gets its name from the term "radio detection and ranging." "Ranging" is the term for detection of the distance between an object and the radar set. Besides being of critical importance to pilots, radar is essential for air traffic control, tracking ships at sea, and for tracking weather systems and storms. |
The phrase "a burst" underlined in Paragraph 1 most probably means ______.
A.an attachment
B.a discharge
C.a stream
D.a ray