【单选题】On Buy Nothing Day, people are encouraged ________anything.
【单选题】有一个边长为【图片】的均匀裸立方体堆,堆内热中子通量密度为:【图片】若堆芯内的扩散系数为0.84cm,扩散长度为17.5cm,则单位时间内整个堆芯被吸收的热中子数为___________【图片】个。(结果精确到小数点后4位有效数字)
【单选题】目前关于氧化磷酸化机制的理论获得较多支持的是
【判断题】如果一个函数在被调用之后定义,则必须在调用函数前对函数原型进行说明。
【单选题】The best title for the passage might be ______.
A.
Buy Nothing Day in the U.S.
B.
The Future of Buy Nothing Day
C.
Free Dinners on Buy Nothing Day
D.
Students'Activities on Buy Nothing Day
【简答题】有一个边长为【图片】的均匀裸立方体堆,堆内热中子通量密度为【图片】。若堆芯内的扩散系数为0.84cm,扩散长度为17.5cm,则单位时间内整个堆芯内被吸收的热中子数为___________【图片】个。(结果精确到小数点后4位)
【简答题】有一个边长为【图片】的均匀裸立方体堆,堆内热中子通量密度为:【图片】若堆芯内的扩散系数为0.84cm,则单位时间内从堆芯泄漏的中子数为________【图片】【图片】个。(结果精确到小数点后4位)
【判断题】“Ad. Val.”(Ad Valorem)又称从价运费。
【单选题】If you can make photographs, what can you do to enhance your skills?
A.
Enter photo competitions.
B.
Take as many photos as possible.
C.
Take a community college class.
D.
Learn from other photographers.