Astronomers often need to collect data and observations from distant objects to which it is dangerous for astronauts to travel. Which instrument helps astronomers safely collect samples from distant objects to which they cannot travel?
radio telescope
satellite
space probe
spectroscope

What is the difference between a scientific hypotheses and a scientific theory?

The serengeti plains are part of the african savanna ecosystem and are home to a variety of different species of plants and animals. the serengeti plains experience a seven-month period of seasonal drought each year, during which the ecosystem receives only four inches of rain and the availability of some resources becomes very scarce. which type of limiting factors does the seasonal drought in the serengeti plains affect?

How do you suppose living conditions differ between the country furthest along in the demographic transition compared to the country earliest in the transition? how would living conditions in these two countries affect both birth and death rates?