很简单的语法题,告诉我选项并说明为什么

很简单的语法题,告诉我选项并说明为什么
1.______ receives only a small portion of the total amount of the sun’s energy.
a.The earth’s surface c. The surface of earth
b.The surface earth d. The earth surface
2.He has written several books, but his last works _____ well known among his friends.
a. haveb. have beenc. isd. are
3.He has done some ______ on that subject from various angles over the past ten years.
a. researchb. a researchc. researchesd. the researches
4.Recently, he has lost all his ______.
a.wage and saving at cardc. wages and saving at card
b.wages and savings at card d. wages and savings at cards
5.It is four months since I last saw Keats ______.
a.at Mrt Smith’s ,the book sellerc. at my aunt’s, a book seller
b.at my aunt’s, Mrs Palmer’s d. at Mrs Palmer’s, the book seller’s