 Which is correct? Number 1. His research, the study of plants. Bases of, based of, is based on, is based of. What's the best answer? C is based on. Number 2. Our company, Italy, is based in, is based to, is based on. Is based by, is based with. The best answer is A, is based in. Number 3. My theory, scientific research, bases about, based upon, is basis upon, is based on. The best answer is D, is based on. Or, her knowledge, years of experience, based on, is based from, are based in, is based on. The best answer is D, is based on. Number 5. What do you, base your conclusion, base your conclusion on. Basing your conclusion on. The best answer is B, base your conclusion on. To learn more about this topic, see video at link. Or, check out our websites for more free English learning resources. eslgold.com and freeenglishstudy.com.