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.

当北京是5月1日5点时，世界是4月30日的地方()

我国稀土矿储量居世界首位，主要矿区在()

实际划分东西两半球的界线是()

下列关于细胞的叙述，错误的是()