Why copper is diffcult to spot welding?

What is the abbreviation for ampere? What will the preferable voltage level for the transmission of 3MW to 30Km.plz justify the answer.? How to find the greatest lower bound in a lattice? How do you control the capacity of a cooling tower? When using an ohm meter to test a surface element an open reading indicates what? What is the formula for calculating DC votage from a 3 phase rectifier bridge using AC voltage across one phase? What is a cost of using technology to transport water A.Crops can be irrigated and grown in new areas. B. Cities can be built in otherwise uninhabitable areas. C. Freshwater supplies can be depleted? Where was the bionic ear invented? What is the minimum number of stacks of size 10 required to implement a queue to size 10? If One wire in a circuit is replaced by a wire that conducts less electricity which unit describes the difference in conduction between the wires? Which was the first hydroelectric dam? Is a wind farm in central Scotland a good idea? Why convergent-divergent used in steam nozzles? What three inventions were made in 1995? Which insulates heat the most paper cotton or aluminum foil? Who invented track housing? What is the Difference between coarse grained and fine grained parallelism? When using water to test a drainage system the maximum feet of head allowed is? How would you design an algorithm for reversing two adjacent entries on a stack if you were given three stacks and you were only allowed to move entries one at a time from one stack to another? What programming language uses a set of grammar and rules that specifies how to write instructions?