下面选项中对提高工字形组合截面梁的整体稳定性作用最小的是( )

A．增加腹板厚度
B．约束梁端扭转
C．设置平面外支承
D．加宽梁翼缘

Will __31_______ matter if you don’t take your breakfast? Recently a test __32________ (give) in the United Sates. Those tests included people of different __33________ from 12 to 83. During the experiment, these people were given all kinds of breakfasts, and sometimes they got __34__________ breakfast at all. Special tests were set up to see ___35________ well their bodies worked and when they had eaten ___36_________ certain kind of breakfast. The results show that if a person eats a proper breakfast, he or she will work with better effect __37_________ if he or she has no breakfast. This fact appears to be ___38_________ (especial) true if a person works __39_______ his brains. For example, if a student eats fruit, eggs, bread and milk before going to school, he will learn more quickly and listen with __40_______ (much) attention in class.