1.他对这个国家的历史时间和人物十分了解.（historical)

　　Heiswellacquaintedwithhistoricaldatesandfiguresofthiscountry.

　　Heknowsverywellaboutthiscountry'shistoricaldatesandfigures.

　　2.警方已收到投诉函件,他们正着手进行调查.（complaint,lookinto)

　　Thepolicehasreceivedtheletterofcomplaint.Andtheyarelookingintoit.

　　3.今天我们要集中讨论无家可归者的问题.（focuson)

　　Todaywewillfocusontheproblemofhomelesspeople.

　　Todaywe’regoingtofocusonthequestionofhomelesspeople.

　　4.电子邮件使全世界间的交流更加便捷.（E-mail,makc...fasterandefficient)

　　Theemailhasmadetheworld'scommunicationfasterandefficient.

　　5.州政府声称已经减免了个人税.（claim,taxation)

　　Thestategovernmentclaimedthattheindividualincometaxationhasbeenreduced.

　　Thestategovernmentclaimedtohavereducedindividualincometaxation.(个人税应该就是个人所得税哇?!)