Annual plants live for one growing season and then die, but perennial plants regrow every spring.
Even before the first warning was issued, it was too late for the inhabitants of the island American Samoa.
Tourists with a smart phone take a picture of an ancient object and then instantly see what it originally looked like.
People living in residential areas with high levels of noise from road traffic appear to suffer more heart attacks.
Two mathematicians have devised what they say is a "surprisingly effective" means to predict the outcome.