In no way ______ from practice.

A:theory can be separated B:theory is separated C:can theory be separated D:has theory been separated

Uniform Customs and Practice for Documentary Credit

Theory is based on practice and( )turn serves practice.

A:in B:by C:at D:on

Theory is based on practice and( )turn 8erves practice．

A:in B:by C:at D:on

Theory is based on practice and( )turn serves practice.

A:in B:by C:at D:on

Safe welding practice requires .

A:checking the area for items that may catch fire B:that a fire watch be posted C:checking for the explosive gases D:all of the above