Generally speaking, _________ main material for building houses has been concrete, but _________ wood and stone have also been used.
If you think that treating a woman well means always her permission for things, think again.
Someone who lacks staying power and perseverance is unlikely to ___ a good researcher.
Don’t respond to any e-mails ______ personal information, no matter how official they look.
I used to quarrel a lot with my parents, but now we ________fine.
The fact that she never apologized ____a lot about what kind of person she is.