某单位委托对一新型食品添加剂进行二阶段毒理学安全性鉴定。急性经口毒性试验结果表明，其一次最大耐受剂量>5000mg／kg，属无毒类。现进入第二阶段试验
在进行实验时，为避免出现假阴性结果，需设立阳性对照组。TA98+S9的阳性对照物为

教学内容难度水平处在幼儿的“最近发展区”之内，说明教学内容的选择符合(  )。

下列哪一选项能反映体育教学工作的基本要求和评价体育教学的标准()。

决定尿量多少最关键的部位是

正常情况下胃黏膜不被胃液消化的原因是 （   ）。

tRNA的3’端的序列为

Passage 2

  That everyone's too busy these days is a cliche.But one specific complaint is made especially  mournfully: There's never any time to read.

What makes the problemthornier is that the usual time-management techniques don't  seem sufficient. The web's full of articlesoffering tips on making time to read: "Give up T"' or "Carry a bookwith you at all times." But in my experience, using such methods to freeup the odd 30 minutes doesn't work. Sit down to read and the flywheel of work-relatedthoughts keeps spinning-or else you're so exhausted that a challenging book'sthe last thing you need. The modern mind, Tim Parks, a novelist and critic,writes," is overwhelmingly inclined toward communication ... It is not simplythat one is interrupted: it is that one is actually inclined tointerruption." Deep reading re-quires not just time, but a special kind oftime which can't be obtained merely by becoming more

efficient.

   Infact, "becoming more efficient" is part of the problem. Thinking oftime as a resource to be maximised means you approach it instrumentally, judgingany given moment as well spent only in so far as it advances progress towardsome goal. Immersive reading, by contrast, depends on being will-ing to riskinefficiency, goallessness, even time-wasting. Try to slot it in as a to-do list item and you 'll  manage only goal-focused reading-useful,sometimes but not the most fulfilling kind. "The future

comes at us like empty bottles along an unstoppable and nearlyinfinite conveyor belt," writes Gary  Eberle  inhis book Sacred Time, and  "we feela pressure to fill these different-sized bottles(days, hours, minutes)as theypass, for if they get by without being filled, we will have wasted them."No mind-set could be worse for losing yourself in a book.

     So what does work? Perhaps surprisingly,scheduling regular times for reading. You'd think this might fuel theefficiency mind-set, but in fact, Eberle notes, such ritualistic behavior helpsus "step outside time's flow" into "soul time." You couldlimit distractions by reading only physical books, or on single-purposee-readers."Carry a book with you at all times" can actually work,too-providing you dip in often enough, so that reading becomes the defaultstate from which you tem-porarily surface to take care of business, beforedropping back down. On a really good day, it no longer feels as if you're   "making time to read", but justreading, and making time for everything else.                  

The usual time-management techniques don't work because_______.

太阳伤寒与太阳中风相同的基本证候有

某选修教材编排有《论语》与《孟子》单元，教师准备重点讲解《四子侍坐》和《齐桓晋文之事》，引导学生深入研读。《四子侍坐》以理解曾皙志向的实质和四子志向之间的关系为重点；《齐桓晋文之事》以探讨孟子的论辩艺术、感知孟子为重点；其他内容由学生课外自主学习，以此完成对“孔孟专题”的教学。该教学设计没有体现出()。

《送杜少府之任蜀州》诗句中的“城阙辅三秦”,“三秦”指的是（）。

与非零售风险暴露相比，下列选项中不属于零售风险暴露特点的是（   ）。