1·VSG is commonly considered a strong immunogen and only enables the immune protection to homotype rather than heterotype.
VSG是公认的强免疫原，但只能使机体产生针对同型虫体的免疫保护，而对异型虫体不起保护作用。
2·The utility model belongs to the mould for producing heterotype steel wires.
本实用新型属于生产异型钢丝用模具。