(C) Animals have been (4) [pushed / pushing] to produce more and more milk, meat, or eggs, and problems with lameness and weakness have already (d) [decreased / increased] since the 1980s...
Medium (4:30 for an oversized 16x15 grid) THEME: stuttered "refrains" — famous "refrains... is super weird. When I was solving this puzzle, I actually thought that was so unlikely...