悬浮物的颗粒较大，它们在水中比较稳定。

已知集合S=R，A={x|x²-2x-3≤0}，B={x||x-2|＜2}，那么集合∁_R（A∩B）等于（　　）

A．{x|0＜x≤3}

B．{x|-1≤x＜2}

C．{x|x≤0，或x＞3}

D．{x|x＜-1，或x≥2}

在一次函数y=﹣2x+5的图象上有两个点A（x₁，y₁）、B（x₂，y₂），已知x₁＞x₂，则y₁﹣y₂（    ）0．

用所给单词的适当形式填空（每空1分，共5分）

grade      fail        great       get        because

Dear Dad ,

The day before yesterday was Father’s Day .I couldn’t celebrate it for you because I was busy taking the high entrance exam . But I have said “I love you, Dad !” in my heart many times .

You are an ordinary (普通的) man ,but in my eyes, you are the小题1:father in the world . Every time I have trouble, you always give me advice and help me out. I remember once I小题2:in a competition ,and I felt very upset . Instead of complaining, you just said to me quietly, “It doesn’t matter . A real man must learn to face many failures (失败) in life bravely .Cheer up !”

Dad,I am not going to buy you anything as a present小题3:I don’t think it express my thanks to you .I’ll try my best to get good小题4:.I think that is the best present you are looking forward to小题5:. I’m sure I won’t let you down .

Hope my dear dad is healthy forever.

根据对患者人身造成的损害程度，医疗事故分为（）级。

A.三

B.四

C.五

D.六

在微机中，西文字符所采用的编码是______。

A．EBCDIC码

B．ASCII码

C．国标码

D．BCD码