According to scientists, our mental abilities begin to __________ from the age of 27 after reaching the highest level at 22.
Every morning I get up at 6:00 because I have two dogs ______ at the door for me to take them out for the routine walk.
Guess what! I came across my primary school science teacher this morning, ______ I have lost touch for almost 20 years.
After Tom had finished some paper work, he ______ interviewing the applicants.
It takes ______ to talk to others on the team when that might expose some of your own weaknesses or ignorance.
______her ambition of becoming a professional singer, she has been training very hard since an early age.