Internet users are warned to be ________ about giving away personal information to strangers

He left his hometown in 1990, and great changes _________ ever since

Nowadays food safety is a big problem and nobody can guarantee all foods are safe to us, but food produced in the normal companies is ______ better

The man is thirsty________money and power．His wife wants him to pay attention to health and family．

.Most birds find it safe to sleep in the trees, but __________ they have eggs or young chicks, they don’t use a nest.