设随机变量(X,Y)服从二维正态分布N(0,0;1,4;-1/2),随机变量中服从标准正态分布且与X独立的是()
A、C
Seniormembersofthestaffcompetedeagerly________thepositionofsalesmanagerinthecompany.
WeweretoldthatSuewouldbeidealforthejob,butshe________badlywhenwetalkedtoher.
Onlywhenyouhaveobtainedsufficientdata________cometoasoundconclusion.
设函数y=e^x+1，则y''=（）
Thefarmerhadtowearheavybootsinthewinterbecausethefieldsweretoowetand________.
