I can’t find my purse anywhere.—You______have lost it while shopping.[ ]

These days I can only sleep for four or five hours at night as I’m too busy with my research work..— If you keep going on like that, you are sure to ______ sooner or later.

I hear that Lily’s brother is a worker here.—Look! The manisworking over there is her brother.

______about her own safety, though she was in great danger herself.

Someone who lacks staying power and perseverance is unlikely to________a good researcher. [ ]