Complete this paragraph regarding dangers from the Sun. X-rays and UV rays from the Sun can disrupt 1)_ radio communication from ground-based radio towers. 2) _ may also be affected by solar particles that can damage equipment. Humans in 3)_ are also susceptible to radiation damage from the Sun. Solar activity can also cause 4)_ that can damage electrical transformers and power stations.

1)
A. Ultra high-radiation
B. High-frequency
C. Low-frequency

2)
A. Aircraft
B. Sea Vessels
C. Satelites

3)
A. Spacecraft
B. Airplanes
C. High Mountains

4)
A. Thermal Heating
B. Geomagnetic Storms
C. Electrical storms

If you need further clarification check the attached image. Thanks for the help.