In the lecture, little Tom kept silent all the time unless _________ to express his opinion.
Teachers have to constantly update their knowledge in order to maintain their professional _____.
“I don’t think it’s my _______ that the TV blew up. I just turned it on. That’s all.” said the boy.
—Look! Somebody _____ the sofa. —Well, it wasn’t me. I didn’t do it.
The success of a government should be measured ____ the health and happiness of the people as well as the development of the economy.
According to scientists, our mental abilities begin to____ from the age of 27 after reaching the highest level at 22.