技术贸易合同履行环节的多少取决于______ A．交易标的的数额 B．交易主体的多

Several children in a kindergarten class have been treated for pinworm. To prevent the spread of pinworm, the school nurse meets with the parents and explains that they should

A. tell the children not to bite their fingernails.
B. not let children share hairbrushes.
C. tell the children to cover their mouths and noses when they cough or sneeze.
D. have their children immunize

对于一些十字形基础仍不能满足整体性要求的软土层、荷载大的重要建筑物，宜采用()基础。

A.独立 

B.肋式墙下条形 

C.柱下钢筋混凝土条形 

D.筏形 

为了防止计算机病毒的传染，应该做到

A．不要拷贝来历不明的软盘上的程序

B．对长期不用的软盘要经常格式化

C．对软盘上的文件要经常重新拷贝

D．不要把无病毒的软盘与来历不明的软盘放在一起

广义农业推广

一个人同时需要做很多事情是资源约束的例子。