I think playing football is a good way to learn the spirit of teamwork （　　）

A．aB．anC．theD．/

The 3﹣D film The Angry Birds opened in Chinese cinemasMay 20，2016（　　）

A．onB．atC．inD．to

My cousin Andrew is crazy about doing many things by （　　）

A．herselfB．himselfC．himD．her

Life is like riding a bicycle．To keep your ，you must keep moving．（　　）

A．promiseB．positionC．balanceD．ability

The rich wereone of the four main classes in the Aztec society （　　）

A．the most powerfulB．the more powerful

C．more powerfulD．powerful