This doubt had been in my mind for some time, but the research still went on _____some reasons.[ ]

Lily, _________ apple on the table is for you.—Thanks, Mum. _________apple a day is good for us.

Peter speaks Chinese than Mary.

Our parents and teachers often ________ the importance of study hard _______ us.

So necessary _____ it to learn about their customs that I will attend a special lecture next week.