WHAT HAS ARMS BUT CAN NOT HUG ?

A LITTLE GIRL KICKS A SOCCER BALL . IT GOES 10 FEET AND COMES BACK TO HER . HOW IS THIS POSSIBLE ?

HOW CAN YOU DROP A RAW EGG ONTO A CONCRETE FLOOR WITHOUT CRACKING IT ?

HOW OFTEN DO YOU COME ... VISIT YOUR UNCLE AND AUNT ?

1 . D , 2 . C , 3 . A , 4 . D , 5 . C

ý 2 tách 2abc thành abc+abc ,rồi làm tương tự ý 1 , phá ngoặc 2 hạng tử ở giữa rồi nhóm để xuất hiện NTC
 

10+10=20