Do remember to be ________. We must avoid any possible risks when doing this dangerous chemical experiment—burns, poisonous gases or cuts from broken tubes.
Great changes ______ in China in the past 20 years.
I’m sorry to say that our food is almost _______.We can’t survive if there is no one to help us.
When the baby was crying, she started singing to him and was ________ with a smile.
Only _______ people can have a good understanding of the lecture given by the scientist.
As is known to all language learners, the newly learnt words will soon be forgotten unless they are _______ used in everyday communication.