How do astronomers test the existence of black holes? do you think you could give some suggestions how to observe what is not visible? if so, what suggestions it would be?

For one week be an inventor and write down ideas for products or services that you think should be produced

Which statement about factories in the industrial revolution is not true? a) some of the first advances were in textile mills b) spinning machines used water power c) water power was replaced by steam power d) coal was imported to english factories for power answer d) coal was imported to english factories for power

Which of the following statements best describes what is occurring in the land surrounding the sahara desert? a desertification is increasing, and the desert is expanding. b. fewer people are trying to farm in this semiarid region. c. the desert is shrinking with the increased use of irrigation. d. increased urbanization has resulted in decreased deforestation. select the best answer from the choices provided mark this and return save and exit next submit