Scientists have spent years into the effects of certain chemicals on the human brain, but with no result.（）
A: studying
B: researching
C: investigating
D: inspecting
A: studying
B: researching
C: investigating
D: inspecting
举一反三
- Scientists have spent years_________ into the effects of certain chemicals on the human brain with no results. A: studying B: investigating C: researching D: inspecting
- 智慧职教: Scientists have spent years ____into the effects of certain chemicals on the human brain with no results.
- Certain diseases of the brain are suffered by human being _____.
- 2. Why do human beings have a larger brain compared to chimpanzees? A: Human beings always had a big brain that helped us to survive. B: Human beings have a bigger brain by cooking food over the fire. C: Human being have a bigger brain through the evolutionary process. D: Human beings have a bigger brain through eating fruits and berries. E: Human beings have a bigger brain through migration.
- The police are _______ the murder. A: examining B: investigating C: inspecting D: searching