单选题 The _____________ cough and headache led to his continual insomnia (失眠).

单选题 Chinook salmon (奇努克鲑) hatch (孵化) in freshwater rivers but _______ out to the Ocean.

单选题 Rich in folklore and stunning scenery, such a vast island is sparsely _______ by about 1,000 people.

单选题 Concerns over the online social network’s new privacy policy have led some faithful users to _________ their accounts.

单选题 Traffic police in Cambodia have not _______ traffic laws for four months due to the election.

单选题 The essence of ________ is the attempt to control the animal instincts of humans to build a better life

单选题 The change in the economic environment makes him in ________ need of big investment.

单选题 With tons of imitation (仿造的), synthetic (人造的) diamonds pouring into the market, it has become necessary to establish a diamond _________ method.