单选题 Scientists have learned more about the ______ effects that human activities have on the environment and climate.

单选题 Let's embrace Chinese culture this summer and get ____ in the richness of traditional Chinese music and dance!

单选题 The Chinese scientific community will ____ with their international peers in frontier science research.

单选题 They are able to take ____ ideas, thoughts, and generalizations and weave them into meaningful patterns.

单选题 The question was how to maintain that kind of ____ for a vehicle that weighed considerably more than 3,300 pounds.

单选题 Doctors consider it their ____ duty to protect and save the lives of their patients.

单选题 Without warning, there was a(n) ____ storm and the waves swept over the boat.

单选题 They needed someone to ____ for a pianist who couldn't make it, and her professor recommended her.

单选题 He entered the film industry, taking small roles and writing ____ for a famous film company.