什么是列车编组计划？列车编组计划编制的原则是什么？

需要评定总长的某一组夹渣，均应处在与焊缝方向平行的一条直线上。在实际评定时，直线两侧一定宽度范围内的条状夹渣也认为在此直线上。对于母材厚度T≤25mm的焊缝每侧宽度范围为（）mm。

A、2

B、5

C、4

D、3

Health officials in western Siberia are to begin in slaughter of thousands of birds today after identifying Russia’s first outbreak of a bird flu strain that can be fatal in humans. Doctors in neighboring Kazakhstan have also (1) that a 19-year-old poultry worker (2) admitted to hospital with (3) of bird flu, only to be diagnosed (4) double pneumonia.
The H5N1 strain of avian (5) has killed 60 people (6) 2fib in Vietnam, Thailand, Cambodia and Indonesia, but has rarely been found in birds or humans (7) Asia.
Health officials (8) that HSN1 is infecting migrating birds, which could spread the (9) into Europe. Earlier this year China registered the first outbreak of H5N1 (10) wild birds, some of which (11) to breeding grounds in Siberia. These birds could come (12) contact with others flying to Europe and North America.
Russia’s (13) began in the Novosibirsk (14) , about 1,750 miles (15) of Moscow in the Asian part of Russia, early last month, but the veterinary service (16) the virus only last week. Valery Mikheyev, the chief sanitary doctor of Novosibirsk, said that teams had been (17) the (18) birds and supervising the slaughter in13 (19) villages. He said, "The state of (20) of the inhabitants of these areas gives (21) cause for alarm. Up to 6,000 people are being (22) per day.
The virus seems to have (23) only private farms that let (24) mix with wild birds. Further outbreaks were registered in the Omsk and Altai regions, but the strain had (25) to be determined, Russia’s Emergency Situations Ministry said.

劳动合同（）即具有法律约束力。

A.书面订立

B.口头订立

C.订立

D.依法订立

血清胆红素测定的标本必须避免阳光直接照射，以免结果降低。其原因是（）

A.胆红素氧化成胆绿素

B.胆红素分子构型改变

C.直接胆红素转变成间接胆红素

D.胆红素分解

E.形成δ胆红素

齿轮泵正常运转时，突然出现出口压力降低甚至归零，其原因可能是（）。

A、泵人口温度高

B、吸入管线漏气

C、泵效降低

D、A、B或C