.It was the four years from 2004-2007, ____ I spent studying for a master’s degree, ____ I will never forget.
Little Tom was so enthusiastic about learning Chinese and after six months, he could speak it ______ fluently.
This is a complex operation. A team of nurses _____ the doctor in performing the operation.
The conflict between economic development and environmental protection, if not appropriately _________, can cause disastrous consequences in daily life settings.
People are always coming in here borrowing my hammer, you know, to fix a cart wheel or ______.
The WHO ________ eat less bacon and other preserved meat because they can cause cancer.