What is the best explanation of motion?
An object changing position over time
A river washing away a bank
Grass growing in the sunlight
A gear turning in a machine
The heterodon had large, sharp canine teeth. What type of food did this dinosaur most likely eat?
Which organism could replace grasshopper in the food web below?
A tiger, a chimpanzee, and a bear all belong to the same group because they all have
Intensity is another way to describe a sound's