The following questions consist of an incomplete sentence that is split into four parts. All four parts are jumbled up and named P, Q, R, and S. These four parts are not given in their proper order. Arrange the jumbled parts of the sentence and find out which of the four combinations from the given options will correctly complete the sentence.

 

The use of powers, ________________inside the testing spectacles’ frame.

 

P. instead of focal lengths,

Q. for lenses is quite convenient for opticians,

R. during eye-testing, an optician puts several different combinations

S. of corrective lenses of known power, in contact