( )38. What does the underlined word "easy" in paragraph 1 probably mean?
A. Practical.
B. Pleasant.
C. Successful.
D. Difficult.
( )39. The researchers ground up a smartphone to ______.
A. draw people's attention to Apple
B. test the quality of smartphones
C. try out a blender they invented
D. find out which elements are used in smartphones
( )40. The researchers are actually concerned(关心的)about ______.
A. providing better jobs for children worldwide
B. countries and areas that are harmed by wars
C. the problems that mining conflict elements brings
D. how much ore is needed for each smartphone
( )41. What can we infer from the passage?
A. Smartphone companies like Apple used to use child labour.
B. The researchers are strongly against the use of smartphones.
C. Smartphones are expensive because they are made of rare elements.
D. Recycling our smartphones is a wiser choice than throwing them away.

38. B
39. D
40. C
41. D