Meanings

unnecessary

to exert (influence)

to the best of my ability, poor though it be

to reach

success or failure (in examinations)

hard to attain to

passing mark

bent back

successful examinee

and

passing (an examination)

to refer to

cash on hand and in banks

reference

investigation (e.g. into someone's guilt)

spread

diffusion rate

diffusion

cheap edition (of a book, etc.)

attempt