一个用于确定诊断的方法最希望有（） A.高灵敏度 B.高特异性 C.重复性好 D.总

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．

Getting your children to study can be a little like getting them to eat their vegetables.

__小题1:__ Make a study time and have it at the same time every day.This will help your kids to learn to schedule their day and will give them a sense of control over how they spend their time.

Allow them to study in blocks of time，such as for half an hour with a five­minute break in the middle.__小题2:__ Ideal(理想的) study times are after dinner or right after school before dinner.

Never allow your children to study in front of the television，as that will encourage passive activity（被动活动）.__小题3:__

You'll also need to help your kids find the right place to study.After you've set up a good study time for little learners，set up a good place where they can get those creative juices flowing.

__小题4:__ Make sure there is a table or a desk and a comfortable chair.

__小题5:__ This includes helping them out with their homework sometimes and being there for them with the answers to any questions.The input（投入） you give your children during study periods will help form a bond（结合，联系） and help make studying enjoyable.

A．Pick a place where your children can study properly.

B．Hold them to the schedule they create for themselves.

C．Finally，spend time with your kids when they're studying.

D．Keep the atmosphere（氛围） light and offer lots of encouragement，too.E．Instead，use TV as a treat or a reward when the homework is completed.

F．Try to stop this bad habit by offering some sort of reward.

G．One of the best ways to form good study habits for your kids is to design a schedule（计划） that they keep to.

如图所示，一个矩形线框放在匀强磁场中能绕OO′轴转动，当线框中通有如图所示方向的恒定电流时，在线框转动90°的过程中(   )

A．ab边和cd边受到的安培力不变，电磁力矩逐渐变小

B．ab边和cd边受到的安培力逐渐减小，电磁力矩逐渐变小

C．ad边和cb边始终不受安培力

D．ad边和cb边受到的安培力逐渐变大，但电磁力矩为零

发射月球探测器存在发射“窗口”，所谓“窗口”既是探测器进入奔月轨道（图中的轨道4）的时刻．为避免错过发射“窗口”，我国的“嫦娥一号”月球探测卫星是在发射“窗口”之前几天发射的．“嫦娥一号”月球探测卫星先由长征系列某型号火箭送入图中的近地圆轨道1，在轨道1上运行适当时间，然后在卫星自带发动机作用下在图中P点变轨进入停泊轨道2，在停泊轨道2上运行两圈后，再在P变轨进入停泊轨道3，在轨道3上又运行两圈刚好赶上发射“窗口”，再一次在P点变轨进入奔月轨道4．根据以上信息结合所学知识判断下列说法正确的是（　　）

A．若“嫦娥一号”卫星在轨道1、2、3上运行通过P点时的加速度分别为a₁、a₂、a₃，则a₁＜a₂＜a₃

B．若“嫦娥一号”卫星在轨道1、2、3上运行周期分别为T₁、T₂、T₃，则有T₁＜T₂＜T₃

C．“嫦娥一号”在P点进入奔月轨道的速度一定大于11.2km/s

D．“嫦娥一号”在P点进入奔月轨道的速度一定小于11.2km/s

（6分）在烷烃分子中的基团：－CH₃、－CH₂－、、中的碳原子分别称为伯、仲、叔、季碳原子，数目分别用n₁、n₂、n₃、n₄表示。例如：分子中，n₁=6，n₂=1，n₃=2，n₄=1。试根据不同烷烃的组成结构，分析出烷烃(除甲烷外)各原子数的关系。

(1)烷烃分子中氢原子数n₀与n₁、n₂、n₃、n₄之间的关系是n₀=_________________。

(2)四种碳原子数之间的关系为n₁=_________________________________________。

(3)若分子中n₂=n₃=n₄=1，则该分子的结构简式可能为(任写一种)________________。

镜检时，如何区分基内菌丝与气生菌丝？