近几十年来，由于人类消耗的能源急剧增加，森林、草原遭到破坏，大气中二氧化碳的含量

已知两条线段的长度分别为7cm，11cm，当第三条线段的长度为（    ）时，这三条线段可以构成三角形（写出一种既可）。

由两样本均数的判别来推断两总体均数的差别，所谓差别有显著性是指（）。

A.两样本均数差别有显著性

B.两总体均数差别有显著性

C.两样本均数和两总体均数的差别都有显著性

D.其中有一个样本均数和总体均数的差别有显著性

E.两样本均数和一个总体均数的差别有显著性

Dear God，

Now that I am no longer young，I have friends whose mothers have passed away．I have heard these sons and daughters say they never  2 1  appreciatedtheir mothers until it was too  22 to tell them．

I am  23 with the dear mother who is still allve．I appreciate her  24 each day．My mother does not  25 ，but I do．  26   I grow older and wiser．Irealize what a(n)  27 person she is．How sad that I alil    28  to speak thesewords in her presence，29 they flow easily from my pen．

How does a daughter begin to thank her mother for giving her llfe I  30’ For the love，patience and just plain hard work that go into  3 l  a child? For32 a toddler，for understanding a moody teenager，for tolerating a college student who thinks she knows  33？ For waiting for the day  34  a daughter realizes her mother really is？

How does a    35   wonlan thank for a mother for continuing to be a mother？For being ready with advice (when asked ) or  36  silent when it is most appreciated? For not saying:”I 37you so ,”when she could have spoked these words dozens of  38   ?For being essentially herself-loving ,thoughtful. Patient, and forgiving?

I don’t know how，dear God，except to bless her as richly as she  39 and to help me live up to the example she has set．I pray that 1 will look as good in the eyes of my  40  as my mother looks in mine．

A daughter

21．A fully             B．truly           C．painfully          D mainly

22．A．early           B．slow            C．1ate             D．fast

23．A．satisfied        B．prepared         C．worried           D blessed

24．A much            B．more            C．1ess             D．fewer

25．A．stand           B．move           C．change           D exist

26．A．As             B．With           C．For              D．Because

27．A．ordinary        B．usual           C．strict            D extraordinary

28．A．unable         B．able            C．eager            D ready

29．A．therefore       B．otherwise        C．but              D．however

30.A herself      B．itself       C．themselves    D．oneself

31.A．punishing    B．blaming     C．raising      D．praising

32.A．running after  B．running across    C．running out     D．running for

33 A．something   B．everything    C．anything      D．nothing

34．A．that          B．when             C．in which           D．where

35 A．grown         B．pleased            C．trained           D．well-behaved

36 A interrupting    B．disliking       C．representing    D．remaining

37．A．asked        B．told              C．ordered            D required

38．A．times       B．days              C．months             D years

39．A．gots        B．gives              C．deserves           D．delivers

40.A．husband   B．children        C．relatives     D．neighbours

苯二氮类药物的作用特点是()

A．对快动眼睡眠时相影响大

B．没有抗惊厥作用

C．没有抗焦虑作用

D．停药后代偿性反跳较重

E．可缩短睡眠诱导时间

早期因果分析法（技术）常运用于项目管理中，就是以结果作为特性，以原因作为因素，逐步深入研究和讨论项目目前存在问题的方法。因果分析法可交付的成果就是因果分析图。一旦确定了因果分析图．即达成了因果分析的目的。请你谈一下现代因果分析流程。