从方法学角度，队列研究属于（）。 A.实验性研究 B.相关性研究 C.描述性研究 D

我国《合同法》规定，依法成立的合同，自( )生效。

A．成立时
B．期限届至时
C．签订时
D．期限届满时

根据短文内容，从短文后的选项中选出能填入空白处的最佳选项。选项中有两项为多余选项。

Three Healthy Ways to Help Your Kids Excel in School

  小题1:    Follow these golden rules to help ensure that your kids succeed this school year—and beyond.

1. Add exercise to their routine.

According to recently published research, the parts of children’s brains that are associated with memory and learning are larger in those kids who are more active.   小题2:     In other words, if you want your kids to get better grades as a result, make sure to schedule in frequent exercise along with piano practice and Mandarin lessons.

2. Feed them healthy food.

Children’s brains need much more nutritious materials to keep developing. A great amount of fish, eggs, nuts, berries, fruits, and vegetables in your kids’ diet will lead to well-nourished (营养良好的) brains as well as bodies.   小题3:    Limiting sweets prevents sugar rushes and low-blood-sugar crashes that can cause kids to become absent-minded and behave irregularly.

3.  小题4:    

While their bodies are asleep, children’s brains are hard at work going over the new information. Kids who don’t get enough sleep or are frequently interrupted while sleeping have been shown to have difficulty remembering what they’ve learned in school.   小题5: That will go far towards helping them be at their best throughout the school d

A．Make sure they get a good night’s sleep.

B．Powerful brains come from healthy bodies.

C．Help your kids go over their lessons before they go to bed.

D．Eating more sugar is key to helping them regulate their behavior as well.E.Help your kids relax in the evenings and go to bed at a reasonable hour.

F.Cutting down on sugar is key to helping them regulate their behavior, too.

G.Studies have shown that children involved in more exercise improved in math, reading, and spelling.

在（）条件下，加权算术平均数等于简单算术平均数。

A.各组次数相等

B.各组变量值不等

C.变量数列为组距数列

D.各组次数都为1

E.各组次数占总次数的比重相等

带传动中的打滑,总是在小轮上先开始。

在突发事件发生期间出现下列（）行为由公安机关或者工商行政管理部门依法给予行政处罚构成犯罪的依法追究刑事责任。

A.散布谣言

B.哄抬物价

C.欺骗消费

D.扰乱社会秩序、市场秩序