Earth yesterday and today
Life on Earth Has Changed. Many kinds of animals that used to live on Earth are no longer living. They are extinct. Reasons for Extinction: Big changes in the climate. Many times animals could not handle these big changes in the weather. Good news: Many animals have adapted to many changes that happen on Earth so that they CAN survive and NOT become extinct! Read More...
◂Science Worksheets and Study Guides Second Grade. Earth yesterday and today
Study Guide
Earth yesterday and today 
Worksheet/Answer key
Earth yesterday and today Worksheet/Answer key
Earth yesterday and today Worksheet/Answer key
Earth yesterday and today Vocabulary/Answer key
Earth yesterday and today
Worksheet/Answer keyWorksheet/Answer keyWorksheet/Answer keyVocabulary/Answer keyThe resources above cover the following skills:
LIFE SCIENCE
Ecosystems: Interactions, Energy, and Dynamics
Plan and carry out an investigation, using one variable at a time (e.g., water, light, soil, air), to determine the growth needs of plants.