These viruses, if ________ in, can result in illness or even death.
A great welcoming party was held yesterday ________ the visiting president, Mr. Xi Jinping.
_______ part that vocabulary plays in learning _______ foreign language should never be ignored.
No judgement ________ about the case until all the evidences have been carefully checked.
Under the environment of fierce competition, the only way John could imagine _______ stress was to get tougher by making greater efforts.
The old farmer______ farm we spent a happy weekend was spellbound by Chinese culture.