An old scientist whom everybody in
England knows very (well, good) is travelling (on, by) train. The
ticket-collector (is making, makes) his round. When he comes to the scientist
and asks him for the ticket, (the, an, -) old man begins to look (at,
for, though) it in his pockets, in his bag and suitcase, but (cannot,
may not, must not) find it anywhere.

"(There, It) doesn't
matter", says the ticket collector, who knows the scientist very (well,
good)." There, is no hurry. I (may, can, should) come again (at,
on, in) the next station". "Oh! But I (can, must, could) find
it", says the old man (helplessly, helpless). "I want to know
where I (go, am going)".