Questions on survey questions on health

A self-locking separable seam assembly comprising a pair of strips of identical J-shape in cross section extruded from semirigid thermoplastic material featuring a thick semirigid return bend portion bordered by a relatively thin low-height lip positioned to interfere with the corresponding lip of the other strip as the strips are pulled crosswise of one another into interlocking engagement. The seam separates as the two strips are forced past one another in a direction opposite to the assembly operation.