Discuss the uses of different shaped hollow blocks. What type of curing method is adopted for precast concrete units? What is timber? Name three types of timbers. Explain the basic structure of a...

Discuss the uses of different shaped hollow blocks. What type of curing method is adopted for precast concrete units? What is timber? Name three types of timbers. Explain the basic structure of a tree. How are trees classified? With a sketch explain the different parts of an exogenous tree.