在匀强磁场中有一个原来静止的碳14原子核,它放射出的粒子与反冲核的径迹是两个相内

题型:选择题

问题:

在匀强磁场中有一个原来静止的碳14原子核,它放射出的粒子与反冲核的径迹是两个相内切的圆,如图所示.那么碳14的衰变方程为(  )

A.+

B.+

C.+

D.+

考点:带电粒子在匀强磁场中的运动α衰变β衰变半衰期
题型:选择题

目前,我国虽然与许多发达国家签有双边贸易协定,但是中国的出口仍然成为各种歧视贸易措施的目标,仍然面对着各种歧视性数量限制、选择性保障措施,以及建立在歧视性标准基础上的反倾销和反补贴措施。这段话主要说明了( )。

A.针对各种歧视性贸易,我们应该制定各种保障措施

B.中国的出口,应避免成为各种歧视性措施的目标

C.面对种种歧视性的措施,我们也不得不建立反倾销和反补贴措施

D.许多发达国家仍针对中国的出口产品制定种种具有歧视性的贸易措施

题型:选择题

下列属于青年消费者的心理特征表现的是( )。

A.购买有主见,不受外界影响

B.理智性胜于冲动性

C.追求科学与实用

D.计划性多于盲目性

题型:选择题

在Linux系统中可用Is-al命令列出文件列表,______列出的是一个符号连接文件。

A.drwxr-xr-x 2 root root 220 2009-04-14 17:30 doe
B.-rw-r-r-- 1 root root 1050 2009-04-14 17:30 doc1
C.lrwxrwxrwx 1 root root 4096 2009-04-14 17:30 profile
D.drwxrwxrwx 4 root root 4096 2009-04-14 17:30 protocols

题型:选择题

Developing reliable software on time and within (106) represents a difficult endeavor for many organizations.
Usually business solutions have three main aspects: people, (107) , and technology. The main reason for failing software projects has little to do with .technology and tools, and much to do with lack of process (108) . Experience has shown that introducing new technology and tools in an immature or undisciplined environment is likely to increase the chaos. CASE tools are not enough. "A fool with a tool is still a fool!"
Structured method was the first wave of the software industry. This was the beginning of transforming software development from a" (109) industry to mass production. Software process movement if the second wave in the software industry. The process maturity movement prepares the way for the third wave of the software industry: "software industrialization". Software development will become like an assembly and manufacturing process. A critical enabling factor is a disciplined software engineering process with predictable quality, (110) and functionality.

A.forecast

B.preparation

C.budget

D.economy

题型:选择题

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