问题 单项选择题

网络计划图由 (51) 组成,如果某工序的工期为0,则表示 (52) 。在非确定型网络计划图中,工期不是确定数,一般需估计三个数值:乐观估计时间a,最可能估计时间m,悲观估计时间不。如假定m与a的加权平均值为(a+2m)/3,m与b的加权平均值为(2m+ b)/3,当这两个时间以相同概率出现时,则可计算出工期的加权平均值 (53) ,以此作为工期,从而把非确定型问题化成确定型问题。

在下图表示的网络计划图中,关键线路是 (54) ,全部计划完成时间是 (55)

(54)处填()。

A.11→14→17

B.11→13→16→17

C.11→12→15→17

D.11→12→14→15→17

答案

参考答案:B

阅读理解

 With the popularity of Harry Potter novels, the number of children applying to boarding schools has risen, many of them hoping to find their own version of Hogwarts. However, others have interpreted this trend as a reaction to longer working hours and the break up of more marriages. The boarding schools of fiction are presented as one long midnight feast with pillow fights making firm friendships. However, some people say the reality is children having more homesickness and a lack of individual attention. Modern boarding schools have done much to get rid of the image of the mass dormitories with 40 or more beds in one room, some going as far as providing private rooms with bathrooms. Similarly, they make great announcements for their academic advantage, particularly in light of the increase in exams, homework and university entrance requirements facing children wishing to succeed in the modern world.

Alongside these more conventional schools, two types of boarding schools have also become more popular recently. Sports academies and stage schools seek to cater for children with particular interests and talents, while so-called troubled-teens have been able to turn to a range of religious or wilderness schools to solve their problematic behavior.

Boarding schools allow children a safe space in which to accomplish greater control and independence over their daily lives. Teachers and staff can look after and support but they are unlikely to be over-protective. This can be a great preparation for university or for working away from home in later life as it provides an intermediate step between childhood and full independence.

However, Parents are a child’s most natural support and best role models to learn from. If they are separated from them for long periods of time, this may damage their relationship and leave the child feeling anxious or alone. Schools are unlikely to be able to copy the detailed knowledge of each individual child that a parent has and therefore cannot be as effective in supporting the child.

To sum up, boarding schools have both their advantages and disadvantages, so it is up to you to decide whether to send your children to boarding schools or not.

小题1:. What do we know from the passage?

A.More and more children go and visit Hogwarts on their own.

B.Pillow fights in boarding schools make firm friendships in reality.

C.More children want to go to boarding schools because of Harry Potter novels.

D.There aren’t special schools for the particularly talented children.小题2: What kind of schools may be the most suitable for the so-called troubled-teens?

A.sports academies

B.Wilderness schools

C.Conventional schools

D.Stage schools小题3:We learn from Paragraph 4 that __________.

A.teachers of boarding schools are the best examples for children to learn from

B.children can be more independent if they are separated from their parents

C.parents know their children better than teachers of boarding schools

D.schools are much more effective than parents in supporting children小题4: What is the author’s opinion of boarding schools?

A.Neutral

B.Negative

C.Positive

D.Critical

多项选择题