这名嫌疑人被指控试图在城镇供水系统中投毒。

The suspect was accused of trying to ___poison the town's water supply.

工业废物污染了这条河，毒死了所有的鱼。

Industrial waste has ___poisoned the river, killing all the fish.

有人故意在狗的食物里下了毒。

Someone had deliberately ___poisoned the dog's food.