Obama: Lower Tensions in South China Sea

airstrip – n. an area of land that is used as a runway for airplanes to take off and land

alarm – v. to cause (someone) to feel a sense of danger : to worry or frighten (someone)

defuse – v. to make (something) less serious, difficult, or tense

contribution – n. something that is given to help a person, a cause, etc.

dredge – v. to remove mud from the bottom of (a lake, river, etc.) in order to deepen it or to search for something

pledge – n. a serious promise or agreement