磨音异常，分析原因，如何处理？

抛物线 y=-x²+1 的开口向（     ）。

语法填空 (共10小题，每小题1.5分，满分15分)

阅读下面短文，按照句子结构的语法性和上下文连贯的要求，在空格处填入一个适当的词或使用括号中词语的正确形式填空，并将答案填写在答题卡标号为31～40的相应位置上。

Chinese proverbs are rich and they are still widely used in Chinese people’s daily life.   31  these proverbs there are often interesting stories. For example, the proverb, “plucking up a crop   32 (help) it grow”, is based on the following story.

It is said that a short—tempered man in the Song Dynasty (960—1279) was very anxious to help   33 rice crop grow up quickly. He was thinking about   34  day and night. But the crop was growing much slower than he expected.

One day, he came up with an idea   35  he would pluck up all of his crop a few inches. He did so the next day.

He was very tired   36  doing this for a whole day,   37  he felt very happy since the crop did “grow”  38 (high).

His son heard about this and went to see the crop. Unfortunately the leaves of the crop began to wither.

This proverb is saying we have to let things go in their   39 (nature) course. Being too anxious to help an event develop often   40 (result) in the contrary to our intention.

某公司收入外汇10000欧元，按当日外汇牌价向银行办理结汇，可以收入多少人民币

对诊断肾结核最有意义的检查是

A．腹部平片

B．肾图

C．静脉肾盂造影

D．B超

E．膀胱镜检

有4只电阻串联，且R1＞R2＞R3＞R4则（）消耗的功率最大。

A、R1

B、R2

C、R3

D、R4