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对划线部分提问,(划线部分)2.(The Class Three students) have just been (t
1年前
异面直线a、b成80度角,P为a、b之外的一定点,若过a、b所成角相等(均为Θ),则Θ的取值范围为?
1年前
U.S.-funded infrastructure deteriorates once under Afghan co
1年前
方程x2+y2=1在空间直角坐标系中表示____________,在平面直角坐标系中表示__________
1年前
One of them knelt on the ground,held out his hand and said,"
1年前