1.Most wild almond seeds contain an intensely bitter chemical called amygdalin, which (as was already mentioned) breaks down to yield the poison cyanide.

多数野生杏仁种子含有一种叫做苦杏仁苷的强烈苦味学物质，它（如前所述）会分解产生有毒的氰物。机翻

2.The explanation is that occasional individual almond trees have a mutation in a single gene that prevents them from synthesizing the bitter-tasting amygdalin.

解释是，偶尔个别杏仁树的单个基因发生突变，导致它们无法合成苦味的苦杏仁苷。机翻