1.After a big debate, Oswiu threw his weight behind the Roman church. "Throw weight behind" - to support something, especially if you use your skills/money/influence etc to help support it. Example >> After a big debate, Oswiu gave used his social influence support to the Roman Church. Oswiu --- > Oswin? 2.There is a business in bank called ”Loan and Lend” but i think there is no difference between these two word. So can i use Borrow to instead of “Lend”? >> Borrow, lend and loan are all slightly different. -- Borrow is the action of taking something from someone with permission & intention to give it back. "Ana borrowed $5000 from the bank to fix her house." --Lend is the action of giving something to someone with the intention/expectation to get it back. "The bank lent Ana $5000 to fix her house." -- Loan is a noun referring to the thing which is borrowed/lent. "Ana took a loan from the bank to fix her house." I think American English also can use "loan" as a verb in certain circumstances. 3.But the balance of opinion accepts Asser’s Life as a genuine, if biased, biography. In this case, does “if means though”? > Yes, in this case. You can also say "...as a genuine, though/but/if biased, biography." 4.an ideal way in which the young man could learn the ropes of ruling before taking on the big task of governing the whole country. Here, i think “ropes” means methods, isn’t it? ->> "To learn the ropes" means "To learn the basic skills" or "To master the introductory knowledge". "Work slowly and cautiously until you have learned the ropes." There are several phrases like this: "know the ropes" and "teach/show someone the ropes". They all come from expressions talking about how experienced sailors were.

#1 = Yes #2 = Lending is when a lender gives someone else money. Borrowing is when a person receives the money from the lender. #3 = Yes #4 = Yes