在平面直角坐标系中描出下列各点，用线段将各点依次连接起来：A

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问题解答题

在平面直角坐标系中描出下列各点，用线段将各点依次连接起来：A（2，5），B（1，3），C（5，2）．并求出该图形的面积．

答案

如图，分别过A、B、C三点作x轴的垂线，垂直分别为D、E、F，

则S_△ABC=S_梯形ADEB+S_梯形ADFC-S_梯形BCFE

×（3+5）×1+

×（2+5）×3-

×（2+3）×4

=4.5．

填空题

根据句意和括号内单词提示，在空白处填入其适当形式，必要时可加其它的单词。

1. She has to make some very difficult __________ (decide).

2. I don't answer questions about my __________ (person) life.

3. She lay _________ (wake) last night, thinking of the matter.

4. You should be careful when you _________ (cross) the street.

5. They seem _________ (know) what they're doing.

6. I ________ (not see) my aunt for 16 years.

7. You know that I don't like ________ (argue) over money.

单项选择题

五脏中，最易导致气机郁滞的是（）

A.心

B.肺

C.脾

D.肝

E.肾