question_answer

Which of the following pairs are correctly matched?

1. Lead.......... screw nutphosphor bronze.

2.  Piston..........cast iron.

3. Cam..........EN-31 steel.

4. Lead screw..........wrought iron.

Select the correct answer using the codes given below:

A) 2, 3 and 4                     

B) 1, 3 and 4

C) 1, 2 and 4                     

D) 1, 2 and 3