Some mysteries remain in desert research,especially relating to why some regions once fertile are now ---------------------

As he was ------------------ and had saved enough money,his family escaped misery when he died suddenly

After they -----------lunch,the boys ran outside

Having secured the highest marks in the class,---------------------

---------------- if he is willing to fit in with the plans of the group

'His parents died when he was young.I think that's why he has --------------- problems'