What strategies and electromagnetic frequencies are thought to be the most logical for long-range communication across the universe with other intelligent beings? a.  explosion of nuclear devices at specific intervals and in specific patterns across earth when we are closest to a nearby starb.  night-by-night photography of nearby stars at hydrogen balmer wavelengthsc.  continuous radio and microwave listening and transmitting at frequencies at which the natural radio sky noise background is lowd.  x-ray surveys of space at appropriate times (e. g., when earth is closest to nearby stars in its orbit), in view of the penetrability of space at these wavelengths

The answer is C. The widely used technique for finding extraterrestrial life is use of SETI (search for extraterrestrial intelligence) dishes that listen for radio waves from outer space. NASA has also been sending radio waves to outer space with messages that could purportedly be decoded by alien intelligent life.

european union policies. the eu's long-term objective is to achieve levels of air quality that do not result in unacceptable impacts on, and risks to, human health and the environment. eu policies aim to reduce exposure to air pollution by reducing emissions and setting limits and target values for air quality.

the main environmental problems in western europe were: energy production/acid rain, nuclear power/waste, air pollution/climate, heavy metals, pesticides, water pollution, solid waste, and unforeseen accidents. many environmental problems are common to most european countries.