I think you mean roof trusses? They are a structural framework of timbers designed to bridge the space above a room and to provide support for a roof. Trusses usually occur at regular intervals, linked by longitudinal timbers such as purlins.
It was never formally approved, it acted as the governing policy for mandatory palestine between 1939 and 1945
Answer:
A nonacademic use of research methods
Explanation:
Although the advantages of silicone over wire might seem obvious, kitchenware makers were unaware of the problems with wire tools until they hired ethnographers to visit people at home, see how they worked in the kitchen, and determine what sorts of things could be sold to them.
This ethnography is an example of a nonacademic use of research methods.
