Former IOC (the International Olympic Committee) president Samaranch’s death is believed ____ by heart attack.
"It's a such nice place," Mother said as she sat at the table________ for customs.
The research lacks evidence, and therefore, its conclusions are doubtful.
We live in an age more information is available with greater ease than ever before.
I think Tom, as the head of a big department, should either study regularly or______ his job.
Youras a student will be excellent if you develop a habit of reflecting on how you learn.