1. Despite trying his best to persuade people to give up smoking, he could not succeed. (verb 'to be' not required- also changed end of sentence to succeed (a verb which means to gain success ) 2. His suggestions were ___________ nobody took any cognizance of them. "So" or "very" can work here, however change "cognizance" with "notice". Either a or b are now correct: a. so trivial that b. very trivial hence ( "so" or "therefore" instead of hence - hence is rather formal for speaking )

B for both. With 1, a doesn't make sense. I have only heard the words 'being tried' when you are going to court for a crime they are charging you with . For 2.a, 'so trivial ' would be used like this:his suggestions were so trivial that nobody took any cognizance of them. Or the 'that' can be omitted and replaced with a comma.