Immunoprotection
免疫保护法
🗣️ 情景例句
Well, what do you think?
嗯，你觉得怎样？
To roar
吠叫
From 1830 onwards in the USA and from about 1870 in Canada, settlers began to move westwards and to take possession of the plains as their own.
美国自1830年起，加拿大从1870年左右起，殖民者开始向西迁移，并把平原据为己有。