题干
When the journalists caught up with the soldiers along the broken road finally,they ___ towards the earthquake - hit town at high speed.
A：advanced
B：were advancing
C：are advancing
D：were advanced
答案(点此获取答案解析）
B
中使人、畜致病，毁伤农作物的微生物及其毒素。通常包括致病菌、立克次氏体、衣原体、病毒、真菌和毒素六大类。根据它们的类型，预测下列属于生物武器危害性特点的是（ ）