He was well-built, but too fleshy to be impressive.他肌肉发达，但是太胖了，没给人留下好印象。I struggled, but he was a tall man, well-built.我使劲挣扎，但他又高又壮。Mitchell is well built, of medium height, with a dark complexion.米切尔体格健壮，中等个头，肤色黝黑。...
这就像是一种化学试剂.It is like a chemical reagent.这种双用试剂把蛋白质分子彼此连接起来.This bifunctional reagent links protein molecules to one another.碳容易被亲核试剂进攻.The carbon should be susceptible to attack by a nucleophilic species....