The number of COVID-19 cases reached its ______ in December before starting to decline.
peak
This research ______ the long-term effects of air pollution on human health.
concerns
The source of the infection was ______ contaminated food at a local market.
traced back to
Some bacteria release a dangerous ______ that can cause severe illness.
toxin
Many species have gone ______ due to habitat destruction and climate change.
extinct
The government built a ______ to control flooding and generate electricity.
dam
Some ______ live inside the human intestines and absorb nutrients from their host.
parasites
After a long illness, it took several months to ______ her strength and energy.
restore
The sudden outbreak of the new virus led to a serious ______ worldwide.
health crisis
You should wash your hands after you ______ someone who is sick.
come into contact with
