There are I’s here, of course:
_ E _ / _ E N I O R / _ I T I _ E N _ / _ O O _ / _ O _ E R / _ E R T _ _ / O N _ I _ E.
There are I’s here, of course:
_ E _ / _ E N I O R / _ I T I _ E N _ / _ O O _ / _ O _ E R / _ E R T _ _ / O N _ I _ E.
Hmm. “Z”, please.
Yes, there is one.
_ E _ / _ E N I O R / _ I T I Z E N _ / _ O O _ / _ O _ E R / _ E R T _ _ / O N _ I _ E.
“C”, if you please.
Yes, there is a C. 
_ E _ / _ E N I O R / C I T I Z E N _ / _ O O _ / _ O _ E R / _ E R T _ _ / O N _ I _ E.
OK, “S”. This one is a puzzler.
There are three of them:
_ E _ / S E N I O R / C I T I Z E N S / _ O O _ / _ O _ E R / _ E R T _ S / O N _ I _ E.
And a ‘K’?
There is a K, indeed.
_ E _ / S E N I O R / C I T I Z E N S / _ O O K / _ O _ E R / _ E R T _ S / O N _ I _ E.
Perhaps an ‘H’ or two?
Sure. 
_ E _ / S E N I O R / C I T I Z E N S / _ O O K / _ O _ E R / _ E R T H S / O N _ I N E.
I’ve just discovered that I had forgotten to write an N.
I will lift the strike as a self-penalty.
Zero strikes.
How 'bout an L?
And a B?
Yes, indeed.
_ E _ / S E N I O R / C I T I Z E N S / B O O K / L O _ E R / B E R T H S / O N L I N E.
“W”, I guess?
A good guess. 
_ E W / S E N I O R / C I T I Z E N S / B O O K / L O W E R / B E R T H S / O N L I N E.
F, please.
F E W / S E N I O R / C I T I Z E N S / B O O K / L O W E R / B E R T H S / O N L I N E.
@bibliophage, congratulations! Please post the next sentence. 
Yes, it is a complete sentence. Thank you for asking.
/ _ / _ _ _ _ / _ _ / _ _ / _ _ _ _ _ _ _ / _ / _ _ _ _ _ _ / _ _ / _ _ _ / _ _ _ _ _ _ / .
I shall break the ice and guess A, please.