英语听力精选进阶版 14182（在线收听）

Battle of the bedbugs

Vocabulary

itchy

unpleasant feeling on the skin that makes you scratch

welts

area of raised skin, red in colour, sometimes caused by an insect bite

calling card

evidence that something has been there

infestations

problems where insects are in a place and causing damage

insecticides

chemical substances used for killing insects

penetrating

getting inside of

mutations

changes in the genes that make it different from others of its type

toxins

poisons

formidable

impressive or powerful

exterminators

people who kill unwanted pests (such as insects)