I found       difficult to make good friends with them.

In his lecture, the professor referred to the belief, in contrast to all other countries, ______ the elderly are wise, ______ is particularly dominant （占优势的） in the Chinese culture．

The family quarrelled about ___ shares the whole night.

Some children don’t like    when their parents try to join their circle of friends.

Mother came into my study with a cup of milk in one of her hands, and an apple in ______.