Giup mình với Chọn câu đúng 1. Each country sends its best athletes_________ participation expresses the friendship and solidarity A. whom B. who C. which D. whose 2.Since I left Venezuela six years ago, I ________ to visit friends and family several times A. am returning B. return C. will have returned D. have returned 3.Neil Armstrong was the first man to walk on the moon ______ 20 July 1969. A. in B. at C. on D. for 4.She spends much time ________by heart new words. A. to learn B. to be learned C. learning D. learn 5.“ I’ll help my mum with housework this weekend” she said A. She said she would help her mum with housework that weekend B. She said she would help her mum with housework this weekend C. She said she will help her mum with housework that weekend D. She said she would help my mum with housework this weekend