Under the selection pressure of crude toxin filtration, three kinds of treatment methods and four kinds of phytotoxin concentrations were used to screen the blast-resistant callus phenylalanine.
I could remember their bodies heavy under winter coats, their hands chapped and callused, their faces—white, Black, brown—betraying the quiet desperation of men who'd lost their purpose.
" How're you doing, Harry? " said the nearer of the two, grinning at him and holding out a large hand, which Harry shook, feeling calluses and blisters under his fingers.