Answer:
Researchers have access to few longitudinal studies and many of them have totally contradictory results.
Step-by-step explanation:
Paraphrasing a sentence is a very simple thing to do. First, it is important that you read the sentence you want to paraphrase. After reading, you must understand the message that this sentence, or text, wants to convey to the reader.
Once you understand the message, you will rewrite that sentence, using other words and your own sentence structure, while maintaining the message that you captured while reading the original text.