JackisateacherofEnglish.Heisnotyoung，butheisnotold.Hehasaroundfaceandblackhair.Heistall.Therearefiftystudentsinhisclass.Theyalllikehim.Nowit'sintheafternoon.Look，somestudentsareworkingintheclassroom.Jackisthere，too.HeishelpingthemtostudyEnglish.Heisagoodteacher，andheisagoodfriendofthemall.

()1.WhatdoesJackdo?

A.Heisaworker.

B.Heisateacher.

C.Heisadoctor.

D.He'sanurse.

()2.Whatcolourishishair?

A.It'sblack.

B.Hisheiriswhite.

C.Itisbrown.

D.Hehasyellowhair.

()3.Howmanystudentsarethereinhisclass?

A.Therearefifteenstudentsinhisclass.

B.There'sfifty.

C.Hehasfifty.

D.There'refiftyinit.

()4.Jackisagoodteacher，isn'the?

A.Yes，heisn't.

B.No，heis.

C.Yes，he's.

D.Yes，heis.

()5.Whatarethestudentsdoingintheclassroom?

A.Theyarewalkingthere.

B.Theyaredoingtheirlessons.

C.Theyarehelpingtheirteacher.

CanIhave_____water?

绿色荧光标记的X染色体DNA探针(X探针)，仅能与细胞内的X染色体DNA的一段特定序列杂交，并使该处呈现绿色荧光亮点。同理，红色荧光标记的Y染色体DNA探针(Y探针)可使Y染色体呈现一个红色荧光亮点。同时用这两种探针检测体细胞，可诊断性染色体数目是否存在异常。医院对某夫妇及胎儿的体细胞进行检测，结果如下图所示。下列分析正确的是

阅读理解，根据短文内容判断正(T)误(F)。

It'sSundaymorning.ThestudentsofClass3aregivingtheirclassroomagoodcleaning.

MissHuang,theirteacher,isworkingwiththem.Thechildrenarebusy.Somearecarryingwater;

somearecleaningthewindows;othersaresweepingthefloor.ZhangHuaisputtingupamaponthe

wall.ItisamapofChina.WangFeiandWeiQingaremendingsomebrokenchairs.Thechildrenare.

listeningtotheradiowhiletheyareworking.Theclassroomlooksniceandbrightafterthecleaning.

Thechildrenareveryhappy.Theygohomeforlunchatnoon.

()1.ThechildrenareplayingintheirclassroomonSundaymorning.

()2.MissHuang,theirmother,isworkingwiththem.

()3.ThereisamapofChinaonthewall.

()4.Twoofthemarerepairingthebrokenchairs.

()5.Theyaresingingwhiletheyareworking.

Theboysaresittingunderthetree.(对划线部分提问)

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