Thistest________anumberofmultiplechoicequestions.

Forthenewcountrytosurvive,________foritspeopletoenjoyprosperity,neweconomicpolicieswillberequired.

设随机变量(Ｘ,Ｙ)服从二维正态分布，且Ｘ与Ｙ不相关，f(x)f(y)XY分别表示Ｘ，Ｙ的概率密度，则在Ｙ＝y的条件下，Ｘ的条件概率密度fX|Y（X|Y）为（）

Theaddressbook________theemailaddressesofyourfriendsorgroupsofcolleagues.

Attendanceatfootballmatcheshave_____sincethecomingoftelevision.