把下列各数填入相应的括号内：
-2.5，10，0.22，0，-

12

13

，-20，+9.78，+68，0.45，+

4

7

．
正整数{　　　　…}，
负整数{　　　　…}，
正分数{　　　　…}，
负分数{　　　　…}．

Dear Benter,
　　You have been away exactly two weeks today but it seems more like two years to me!
　　I’m glad to hear you’ll be back soon. Are you coming directly home, dear? Or do you plan to make some stops   36  the way? I hope you’ll be home in  37 for Patsy’s birthday next Sunday. She is  38 you to show films to her  39 friends.
Patsy keeps asking every day  40 you’ll be back. She says you never  41  that story you were telling her about  42 train that lost its “ toot”(喇叭嘟嘟声). You’d better   43  and think up a good ending  44 it. You know how Patsy is? She  45 be happy until she knows exactly what ­__46  to the “toot” and  47 the little train got it back  48 !
　　Everything at home is fine except that we  49 you so much! I’ve been  50 with the spring cleaning. Yesterday I had Cora  51 in to wash the kitchen walls and she did a very good __52 of it. The kitchen looks as though it’s been repainted. I made some new yellow curtains, and they  53 very beautiful.
　 I went to see your mother yesterday. Her  54 is all gone and she looks very  55 . Your sister Jean looks wonderful! She has taken off about fifteen pounds since she began dieting. But now she’s complaining that none of her clothes fit!
Hope to see you before next Sunday.
　 Love and kisses to you!
　　　　　　　　　　　　　　　　　     Yours
　　　　　　　　　　　　　　　　　           Lynn
【小题1】A in           B. on          C. at          D. along

【小题2】

A．time B．fact C．all D．the end

【小题3】

A．expecting B．thinking C．agreeing D．hoping

【小题4】

A．small B．short C．little D．low

【小题5】

A．that B．when C．why D．unless

【小题6】

A．finished B．stopped C．supplied D．included

【小题7】

A．some B．a C．the D．this

【小题8】

A．care B．arrive C．pretend D．hurry

【小题9】

A．on B．for C．at D．in

【小题10】

A．mustn’t B．couldn’t C．won’t D．shouldn’t

【小题11】

A．affected B．about C．happened D．was

【小题12】

A．how B．however C．because D．why

【小题13】

A．yet B．too C．again D．next

【小题14】

A．love B．think C．miss D．care

【小题15】

A．working B．ready C．together D．busy

【小题16】

A．stay B．come C．visit D．drop

【小题17】

A．work B．job C．thing D．clean

【小题18】

A．show B．feel C．become D．look

【小题19】

A．cold B．heat C．health D．medicine

【小题20】

A．good B．well C．nice D．best

某区八年级有3000名学生参加“爱我中华知识竞赛”活动．为了了解本次知识竞赛的成绩分布情况，从中抽取了200名学生的得分进行统计．

请你根据不完整的表格，回答下列问题：

成绩x（分）	频数	频率
50≤x＜60	10	0.05
60≤x＜70	16	0.08
70≤x＜80	10	0.02
80≤x＜90	62	0.47
90≤x＜100	72	0.36

（1）补全频率分布直方图；

（2）若将得分转化为等级，规定50≤x＜60评为“D”，60≤x＜70评为“C”，70≤x＜90评为“B”，90≤x＜100评为“A”．这次全区八年级参加竞赛的学生约有多少学生参赛成绩被评为“D”？如果随机抽查一名参赛学生的成绩等级，则这名学生的成绩等级哪一个等级的可能性大？请说明理由．