单选题 The research is intended to ______ the relationship between the economy and education.

单选题 It is well-known that China is a country with rich natural ______ and a very long history.

单选题 Some people believe that the earth can ______ enough food to support at least twice its present population.

单选题 The president's speech has ______ the message that the university will do everything to help students prepare for the future.

单选题 There is no room for more furniture in our apartment - we've used up all the space ______.

单选题 From his grandfather, Jack has ______ a love of reading novels and writing poems.

单选题 It was about 30 seconds before Alex ______ from the water; we were quite scared.

单选题 There was widespread concern in the U.S. that the rising unemployment might ______ a threat to social stability.