Spot the intruder

Exercise and reference answers

Questions

1. Items

   1. Hygrometer
   2. Thermometer
   3. Barometer
   4. Richter scale

   Odd item

   Richter scale

2. Items

   1. Perihelion
   2. Aphelion
   3. Equinox
   4. A horizon

   Odd item

   A horizon

3. Items

   1. Water
   2. Road
   3. Pipeline
   4. Humus

   Odd item

   Humus

Instructions

Three belong together. Tap the one that does not.