地下工程

题型:名词解释

问题:

地下工程

考点:土木工程概论土木工程概论题库
题型:名词解释

Let’s try to find out why getting fiber from whole foods is important for a healthy diet. Fiber has never been (67) you’d call a healthy nutrient. Suddenly, it’s a superstar: Manufacturers are (68) it to yogurt, juice, even (69) sweetener.
But as with many (70) , there’s an unseemly back story: Experts aren’t sure that these fiber-boosted foods are (71) trying.
Yes, you should eat lots of fiber. There’s no question that a diet (72) in high-fiber foods is a powerful lifesaver-it’s known to (73) the risk of heart disease and diabetes, and it helps (74) weight gain. Recent studies show a fiber-rich cuts the risk of breast cancer, too, and the (75) you’ll develop cancer of the small intestine. But the new foods might not (76) That’s (77) many of them use "isolated" fiber-stuff that’s been (78) out of the foods that (79) contained it, says nutrition expert Tara Gidus, RD. Isolated fibers are (80) and don’t turn juice and yogurt (81) a delicious, grainy food. The downside: There’s (82) evidence that they protect (83) chronic diseases. So go (84) and try a glass of fiber-boosted grape juice, or stir some (85) into your coffee along with your artificial sweetener. Just don’t forget to also eat more whole grains, beans, and fruits and vegetable-they’re (86) lifesavers.

A.making

B.producing

C.adding

D.laying

题型:名词解释

物体在合外力作用下做直线运动的v-t图象如图所示.下列表述正确的是(  )

A.在0-1s内,合外力做正功

B.在1-2s内,合外力做负功

C.在1-3s内,合外力不做功

D.在0-3s内,合外力总是做正功

题型:名词解释

使用通用对话框控件打开字体对话框时,如果要在字体对话框中列出可用的屏幕字体和打印字体,必须设置通用对话框控件的Flags属性为____。

A.0

B.1

C.2

D.3

题型:名词解释

设R是一个2元关系,S是一个3元关系,则下列运算中正确的是( )。

A.R-S

B.R×S

C.R∩S

D.R∪S

题型:名词解释

有一个CPU和两台外设D1、D2,且能够实现抢占式优先级调度算法的多道程序环境中,同时进入优先级由高到低的P1、P2、P3三个作业,每个作业的处理顺序和使用资源的时间如下:
P1:D2(30ms),CPU(10ms),D1(30ms),CPU(10ms)
P2:D1(20ms),CPU(20ms),D2(40ms)
P3:CPU(30ms),D1(20ms)
假设对于其他辅助操作时间忽略不计,每个作业的周转时间T1、T2、T3分别为多少CPU和D1的利用率各是多少

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