热点试题

如图所示电路中，电源两端电压保持18V不变，小灯泡L上标有“6V 3W”字样，定值电阻R₁＝10W，滑动变阻器最大电阻值R₂＝50W。不考虑灯丝电阻随温度的变化，下列说法正确的是

A．开关S断开时，电压表的示数为18V

B．电路接通后，改变滑片P的位置，小灯泡L的最小实际电功率为0.75W

C．电压表的示数减少1V，电阻R1两端的电压就增加1V

D．小灯泡L正常发光时，变阻器R2消耗的电功率为3.5W

如图所示，AC、BD为圆的两条互相垂直的直径，圆心为O，半径为R.电荷量分别为＋Q、－Q的两点电荷放在圆周上，它们的位置关于AC对称，＋Q与O点的连线和OC间的夹角为60°.下列说法正确的是(　　)．

A．O点的场强大小为，方向由O指向D
B．O点的场强大小为，方向由O指向D
C．A、C两点的电势关系是φ_A<φ_C
D．电荷量为q的正电荷在A点的电势能大于在C点的电势能

已知函数在上的最大值
为1，求的值。

写作展示（５０分）从下面两题中任选一题作文。
（1）请以“从此，我（他／她）不再________”为题，写一篇不少于600字的记叙文。提示：
请将目补充完整，然后作文。横线上可以填写的词语如：任性、自卑、孤独、偷懒、害怕困难、迷恋网络、受人关注、拥有笑容……
（2 ）风雨过后，眼前会是鸥鹭鱼游的天水一色。走出荆棘，前面就是铺满鲜花的康庄大道。登上山顶，脚下便是积翠如云的空蒙山色。在这个世界，一星陨落，黯淡不了星空灿烂；一花凋零，荒芜不了整个春天。
读了上面一段话，你想到了什么？请写一篇不少于600字的文章。题目自拟，体裁不限（除诗歌外）

完形填空(共20小题; 每小题1.5分，满分30分)
阅读下面短文，掌握其大意，然后从所给的 A、B、C、D四个选项中，选出最佳选项，并在答题卡上将该项涂黑。
Time is the easiest thing in the world to waste—the most difficult to control. When you look ahead, it may appear you have 36        you need. Yet it has a way of slipping 37        your fingers like quicksand. You may suddenly find that there is no way to stretch the little time you have 38        to cover all your obligations. For example, 39           a beginning student looking ahead to a full term you may feel that you have an oversupply of time on your hands.40      toward the end of the term you may be 41         because you are running out of time. How can you do? —Control!
Time is 42        . If you don't control it, it will control you. If you don't make it work for you, it will 43        you. You must become the master of time, not the servant. “Study hard and play hard” is an old saying, but it still 44       . You have plenty of time for classes, study, work, and play if you use your time 45        . It is not how much time you allocate for study that 46          but how much you learn when you do study.
Too much wasted time is 47         medicine. The more time you waste, the easier it is to continue wasting time.  Soon, doing nothing becomes a habit you can't 48        . You  will be       49       to wasting time. When this happens, you 50      your feeling of accomplishment and you fall by the wayside. A full schedule is a good schedule. Some students 51          to hear the time message. They refuse to 52        the fact that college life demands some53         of time control. There is no escape. So what's the next step? If you seriously want to get the time message, the next passage will give it to you. 54      — it will not only improve your grades but also free you to 55           college life more.

小题1:	A．less than B．more than C．rather than D．other than

小题2:	A．by B．between C．through D．on

小题3:	A．saved B．left C．remained D．wasted

小题4:	A．since B．because C．for D．as

小题5:	A．Although B．But C．Therefore D．Otherwise

小题6:	A．angry B．brave C．worried D．eager

小题7:	A．money B．friendly C．enough D．dangerous

小题8:	A．work out B．work on C．work at D．work against

小题9:	A．makes sense B．makes no use C．makes up D．makes it

小题10:

A．immediately B．properly C．apparently D．shortly

小题11:

A．counts B．accounts C．approves D．collects

小题12:

A．bad B．good C．useful D．alternative

小题13:

A．get along with B．get close to C．get rid of D．get down to

小题14:

A．crazy B．determined C．addicted D．devoted

小题15:

A．achieve B．appreciate C．loss D．lose

小题16:

A．hesitate B．refuse C．like D．want

小题17:

A．accept B．receive C．ignore D．imagine

小题18:

A．disagreement B．agreement C．degree D．standard

小题19:

A．Forget B．Remind C．Think D．Remember

小题20:

A．hate B．enjoy C．dislike D．assess

（15分）

汽车由静止开始在平直的公路上行驶，0 ~60s内汽车的加速度随时间变化的图线如右图所示。
  ⑴画出汽车在0~60s内的v-t图线；
⑵求在这60s内汽车行驶的路程。