Дополните диалог:
Marsh: What “pests” threaten crops?
Weston: Agronomists use the world “pests” in referring to weeds. Do you know what 1_______ are?
Marsh: Weeds are the plants out of place. They compete with the main crops for nutrients, sunlight and water.
Weston: Besides the weed may be narrow leaf weed, broad leaf weed and sedges which may be annual, biennial or perennial depending upon its life cycle.
Marsh: 2______?
Weston: Insects cause damage by chewing, sucking or piercing plant parts. Did you hear about nematodes?
Marsh: 3_______.
Weston: Nematodes are tiny parasitic worms which are microscopic in nature and invisible to the naked eye. They 4_______ in the plant root system which appears as galls or swollen points on the root system. The injured part may serve as the entry point for several diseases.