Fill the blanks with the prepositions by, with, or by means of sometimes more than one answer is possible. 1. the lumber was transported train. 2. current can be varied in a circuit a rheostat. 3. earthquakes arc usually caused the movement of the continental plates. 4. the age of the sample was determined the carbon 14 dating method. 5. steel surfaces can be protected a thin coating of machine oil. 6. the colours of aurora borealis are generated the effect of solar particles on the various atmospheric gases. 7. the primitive cooling earth was darkened for centuries hot, dense clouds. 8. the direction of growth of a plant is controlled light (phototropism). 9. the body temperature of a higher mammal is regulated the hypothalamus.
by, with, or by means of
2. Current can be varied in a circuit __with__ a rheostat.
3. Earthquakes are usually caused __by__ the movement of the continental plates.
4. The age of the sample was determined __by means of__ the carbon 14 dating method.
5. Steel surfaces can be protected __with___ a thin coating of machine oil.
6. The colours of aurora borealis are generated _by__ the effect of solar particles on the various atmospheric gases.
7. The primitive cooling earth was darkened for centuries __by___ hot, dense clouds.
8. The direction of growth of a plant is controlled __by___ light (phototropism).
9. The body temperature of a higher mammal is regulated __by__ the hypothalamus.