局域网具有低误码率的特点，其误码率一般在()
A、10-6～10-8D
暂无解析
第二类间断点个数()
GeneralMotors,oneoftheworld'slargestautomanufacturers,isexpandingits________inthiscountry.
Iknowitisn’timportantbutIcan’thelp________aboutit.
设曲线y=ax^2+2x在点(1,a+2)处的切线与直线y=4x平行，则a=（）
Othersarguethatsincetheearthhasenduredalongstringoficeagesinthelasttwomilliontothreemillionyears,anywarmingis________tobetemporary.
