单项选择题
If either of you had been able to hold（）your anger, the fight would have been avoided.
A．back B．in C．for D．against
单项选择题 Once he set his mind to（）something, he would not give up easily.
单项选择题 By（）your work environment and personal practices, you may be able to reduce fatigue and discomfort.
单项选择题 The commercial purpose of a trade mark is（）the goods or services of a company from those of competitors.
