The doctors have been operating on his eyes for half an hour till now.
It is hard for the old couple to get by on their small pension.
Understanding spoken English is often difficult because there are lots of varieties of English.
Once the new system is put into use, the productivity will increase.
British English and American English have some differences in vocabulary.
His way of going over his lessons has nothing in common with mine.

Jack spoke enough Chinese to get by during his holiday. (get)
I share a lot of interests in common with my new roommate. (common)
The sun owes us almost everything in this world. (owe)
To tell you the truth, I can't get what you are saying. (truth)
Flooding is one of the factors that contribute to crop loss in this area. (contributes)