Solid geometry proof. . . Strong people will help.

1. Let the plane parallel to A be A and B, and the plane parallel to A be B..

Let another plane passing through A be C, and C is not equal to A, then there is an intersection line between C and B. Let it be C. According to the theorem, C is parallel to A, so C is parallel to plane A, B is parallel to A, and BC is an intersecting straight line, all of which are within B, so B is parallel to A. ..

2. Let the plane be A and B, take any point C on the straight line, let the photography of C on A and B be A and B, then A, B and C are collinear (the proof is abbreviated), and let the intersection of the straight line and the plane be D and E, then A, B, C, D and E are coplanar. According to the theorem, AD is parallel to CE.