Which part of speech does they belong to

Which would be the most credible source for researching the effects of smoking? letter from your grandfather web page about someone’s lung cancer report prepared by a tobacco company research article in a scientific journal

My cat and my dog like best friends

Select the correct answer from each drop-down menu. read the following excerpt from the novel "oliver twist" by charles dickens. although oliver had been brought up by philosophers, he was not theoretically acquainted with the beautiful axiom that self-preservation is the first law of nature. if he had been, perhaps he would have been prepared for this. not being prepared, however, it alarmed him the more; so away he went