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习题1: 环保人员对某城市一个月内的PM2.5值进行检测,得到数据【习题4-1】,回答以下问题:试问该城市的PM2.5水平是否为80? 1 )对该城市的PM2.5水平做参数估计,估计其点估计值和置信区间(置信水平95%)。 2 )检验该城市的PM2.5水平是否等于80。 习题2: 【习题4-2】是某个班30个学生的数学成绩,根据这些数据,问该班男生和女生的数学成绩有无明显差异? 习题3 :为了了解某地在校学生的身高情况,研究小组从当地的四个学校中随机共抽出28个学生,得到他们的身高数据【习题4-3】,根据这些数据,问该地区男生和女生的身高有无明显差异? 习题4: 数据【习题4-4】是关于某个班30个学生,在入学学习一个月后的英语成绩和入学前的英语成绩,试问两者有无明显差异? 习题5: 某学校对高一的数学教学方法进行改革,为了检验改革是否有成效,在高一年级随机抽取了20个学生,比较他们在改革前和改革后的数学成绩,得到数据【习题4-5】,试问本次教学方法改革是否有成效?
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【简答题】The days are getting shorter and shorter, and temperatures are dropping. Winter is coming and it is easy for people to catch flu. Many people have started taking vitamin C pills as a precautionary(预防的...
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【单选题】The jeans are too long. Would you mind give me___ ? [     ]
A.
the shorter pair
B.
a shorter pair
C.
a short pair
D.
the shorter ones
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【多选题】关于施工方编制建设工程项目施工进度计划的说法,正确的有( )
A.
施工条件和资源利用的可行性是编制项目施工进度计划的重要依据
B.
编制项目施工进度计划属于工程项目管理的范畴
C.
项目施工进度计划应符合施工企业施工生产计划的总体安排
D.
项目施工进度计划安排应考虑监理机构人员的进场计划
E.
编制项目施工进度计划属于企业计划的范畴
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【单选题】 import java.util.*；  2. public class TestSet {  3. enum Example { ONE， TWO， THREE }  4. public static void main（String[] args） {  5. Collection coll = new ArrayList（）；  6. coll.add（Example.THREE）；  7...
A.
The set variable contains all six elements from the coll collection， and the order is guaranteed to be preserved.
B.
The set variable contains only three elements from the coll collection， and the order is guaranteed to be preserved.
C.
The set variable contains all six elements from the coil collection， but the order is NOT guaranteed to be preserved.
D.
The set variable contains only three elements from the coil collection， but the order is NOT guaranteed to be preserved.
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【单选题】When winter comes, the days get _____ in Beijing. [     ]
A.
short and short
B.
shorter and shorter
C.
long and long
D.
longer and longer
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【单选题】Russian men live 1 years shorter than Russian women and 16 years shorter than Western Europe men.
A.
Y
B.
N
C.
NG
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【简答题】With the development of ______, the recovery period may become shorter and shorter.
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【单选题】When spring comes, it gets____. A. warm and warm B. colder and colder C. warmer and warmer D. shorter and shorter
A.
warm and warm
B.
colder and colder
C.
warmer and warmer
D.
shorter and shorter
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【简答题】A．nicer B．longer C．better D．shorter
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【单选题】The jeans are too long. Would you mind giving me _____ ? [     ]
A.
the shorter pair
B.
a shorter pair
C.
a shortest pair
D.
the shorter ones
查看完整题目与答案
相关题目：
【简答题】The days are getting shorter and shorter, and temperatures are dropping. Winter is coming and it is easy for people to catch flu. Many people have started taking vitamin C pills as a precautionary(预防的...
查看完整题目与答案
【单选题】The jeans are too long. Would you mind give me___ ? [     ]
A.
the shorter pair
B.
a shorter pair
C.
a short pair
D.
the shorter ones
查看完整题目与答案
【多选题】关于施工方编制建设工程项目施工进度计划的说法,正确的有( )
A.
施工条件和资源利用的可行性是编制项目施工进度计划的重要依据
B.
编制项目施工进度计划属于工程项目管理的范畴
C.
项目施工进度计划应符合施工企业施工生产计划的总体安排
D.
项目施工进度计划安排应考虑监理机构人员的进场计划
E.
编制项目施工进度计划属于企业计划的范畴
查看完整题目与答案
【单选题】 import java.util.*；  2. public class TestSet {  3. enum Example { ONE， TWO， THREE }  4. public static void main（String[] args） {  5. Collection coll = new ArrayList（）；  6. coll.add（Example.THREE）；  7...
A.
The set variable contains all six elements from the coll collection， and the order is guaranteed to be preserved.
B.
The set variable contains only three elements from the coll collection， and the order is guaranteed to be preserved.
C.
The set variable contains all six elements from the coil collection， but the order is NOT guaranteed to be preserved.
D.
The set variable contains only three elements from the coil collection， but the order is NOT guaranteed to be preserved.
查看完整题目与答案
【单选题】When winter comes, the days get _____ in Beijing. [     ]
A.
short and short
B.
shorter and shorter
C.
long and long
D.
longer and longer
查看完整题目与答案
【单选题】Russian men live 1 years shorter than Russian women and 16 years shorter than Western Europe men.
A.
Y
B.
N
C.
NG
查看完整题目与答案
【简答题】With the development of ______, the recovery period may become shorter and shorter.
查看完整题目与答案
【单选题】When spring comes, it gets____. A. warm and warm B. colder and colder C. warmer and warmer D. shorter and shorter
A.
warm and warm
B.
colder and colder
C.
warmer and warmer
D.
shorter and shorter
查看完整题目与答案
【简答题】A．nicer B．longer C．better D．shorter
查看完整题目与答案
【单选题】The jeans are too long. Would you mind giving me _____ ? [     ]
A.
the shorter pair
B.
a shorter pair
C.
a shortest pair
D.
the shorter ones
查看完整题目与答案