I

см. тж. наблюдаться

• Anaplastic cells are derived from adult, differentiated cells.

• This change comes about by virtue of the force acting on ...

• Such explosions come (about) (or occur) each 100 years.

II

см. тж. иметь место; наблюдаться

• No major breakthrough has come about (разг.).

• Most of the world's volcanic activity is found near the boundaries of ...

• We know from experience that this does not happen.

• This process has been going on for 3 billion years.

• The change from melt to crystalline rock happens (or occurs) rapidly.

• Here, fluvial denudation has been in progress for long periods of time.

• Expansion of the clay mass results when more water penetrates ...

• The Mediterranean Sea was the site of extensive evaporite depositions ([lang id=2]B Средиземном море происходили[/lang] ... ).

• Processes of fluvial denudation are at work from the very beginning.

• Such an event will never come to pass.

• Two processes operate simultaneously.

• Every living cell is a seat of numerous metabolic reactions.

• Combustion will occur (or proceed) at any pressure if a suitable catalyst is added.

• If a leak occurs urgent measures should be taken.

• Under these conditions the transformation of heat energy into other forms of energy takes place.

• The 1930s saw a marked spurt in the technological applications of catalysts.

• The past 20 years have witnessed an amazing increase in the number of molecules detected.