Someone who lacks staying power and perseverance is unlikely to ________a good researcher.
I like to go to the opera __________.
After five hours' drive, they reached __________ they thought was the place they'd been dreaming of.
He has given us a suggestion __________ we shouldbuy a cottage in the country with the money we have saved.
There's no __________ in the way they do their accounts(记账).
There are too many difficulties for us __________. Wereally don't know __________ to do.