A:Who is that little girl?
B:Who is that little boy?
已知A-1,0,B1,0两点,过动点M作x轴的垂线,垂足为N,若MN→2=λAN→·NB→,当λ<0时,动点M的轨迹为( )
根据情景提示,用恰当的短语或句子填空。
小科房间门口装有开关S1,床头装有开关S2,这两个开关都能单独控制房间里的吊灯。以下电路图能符合这一要求的是( )
The man likes giraffes _____ they are very interesting.