Answer:
Mary and I <u>am</u> (are) best friends and we have learned English with each other <u>since</u> (for) half a year. Both
of us <u>is</u> (are) highly interested in learning this language due to a number of factors. First of all, learning
English <u>enable</u> (enables) us to understand masterpieces from English speaking countries such as books, <u>movies</u> (add comma) and music. Although Mary is always <u>complain</u> (complaining) that some English grammar structures are too <u>difficultto</u> (difficult) remember, she is always making<u> </u> (a) great effort to learn the language. She often goes to the library to borrow English written books. By now, Mary is reading up to 5 books in English. I <u>am preferring</u> (I prefer) watching movies to reading books. Sometimes, we <u>are talking</u> (talk) with each other in English and share about the books or movies we have just <u>enjoy</u> (enjoyed).
The correct answer to this question is:
"Relative abundance is a comparison between the isotopes and Percent abundance is a comparing the totals." Relative<span> species </span>abundances tend to conform to specific patterns. Percent abundance <span> can be calculated by finding the percentage of an isotope compared to another isotope of an element using its relative atomic mass.</span>
