[多项选择]“数学实验”过程主要包括（）等几个步骤。
A. 建立描述系统行为的数学模型
B. 将数学模型转化成能用计算机作数值运算的形式，并依据初始条件，使模型在计算机上运转
C. 对实验结果进行分析
D. 对实验对象进行调查

Generally speaking, a British is widely regarded as a quiet, shy and conservative person who is (1) only among those with whom he is acquainted. When a stranger is at present, he often seems nervous, (2) embarrassed. You have to take a commuter train any morning or evening to (3) the truth of this. Serious-looking businessmen and women sit reading their newspapers or dozing in a corner; hardly anybody talks, since to do so would be considered quite offensive. (4) , there is an unwritten but clearly understood code of behavior which, (5) broken, makes the offender immediately the object of (6) .
It has been known as a fact that a British has a (7) for the discussion of their weather and that, if given a chance, he will talk about it (8) . Some people argue that it is because the British weather seldom (9) forecast and hence becomes a source of interest and (10) to everyone. This may be so. (11) A. at a loss
B. at last
C. in group
D. on the occasion