Flashing (weatherproofing) bark was occasionally used as a flashing material. Most flashing materials today are metal, plastic, rubber, or impregnated paper. Metal flashing materials include lead, aluminium, copper, stainless steel, zinc alloy, other architectural metals or a metal with a coating such as galvanized steel, lead-coated copper, anodized aluminum, terne-coated copper, galvalume (aluminum-zinc alloy coated sheet steel), and metals similar to stone-coated metal roofing. Metal flashing should be provided with expansion joints on long runs to prevent deformation of the metal sheets due to expansion and contraction, and should not stain or be stained by adjacent materials or react chemically with them.
What Is Life a combination that became the top-selling single of 1971 in that country. "What Is Life" is one of Harrison's most commercial and popular songs – a "spiritual guitar quest" that "became [a] classic", according to "Rolling Stone" magazine. On release, "Billboard" magazine's reviewer wrote of "What Is Life" and "Apple Scruffs" as "intriguing rhythm follows-ups" to Harrison's previous single, which were "sure to repeat that success" and "should prove big juke box items". In their "Solo Beatles Compendium", authors Chip Madinger and Mark Easter refer to it as an "intensely catchy track" and view its pairing with "My Sweet Lord"