Answer:
Tools and machines that are used for farming are Tractors, rake, A machine that they used to pick up corn.
Explanation:
 
        
             
        
        
        
Answer: After the experiment in step 5
Explanation:
In a scientific investigation, first step is to formulate a question. Second step is to do background research. In third step after background research, a hypothesis is constructed. In order to test hypothesis, an experiment is designed and performed. In the fifth step, data is collected from the experiment and in the last step, conclusions are drawn from the collected data. 
 
        
                    
             
        
        
        
Filler Metal is a type of metal used in the fusion welding union, and it is necessary to produce a joint because it serves to collaborate in the opposition, to a greater or lesser degree, against the forces applied to it, without suffering deformation or breakage.
        
             
        
        
        
Answer: The carbon dioxide is the output and oxygen is the input of the Scuba apparatus.
Explanation:
The scuba apparatus is a life saving apparatus used by the sea divers. It recycles the exhaled gas and removes the carbon dioxide and compensates for the utilized oxygen gas before the diver is actually supplied with the gas for the purpose of breathing in a circuit. Hence, the carbon dioxide gas is the output and the oxygen is the input.