Một vật có khối lượng 400g dao động điều hòa có đồ thị động năng như hình vẽ. Tại thời điểm t = 0 vật đang chuyển động theo chiều dương, lấy π 2 = 10 . Phương trình dao động của vật là

A.  x = 10 cos π t + π 6 ( c m )

B.  x = 10 cos π t + π 3 ( c m )

C.  x = 5 cos π t + 2 π 3 ( c m )

D.  x = 5 cos 2 π t − π 3 ( c m )

1, What did you do last night ? We listened to music and watched TV.

2. Where did they go last week ? They went to the cinema.

3. What did her do at the school fesival 3 days ago ? Her enjoyed the shool festival and prepare for the school festival.

4. What did you do last week ? I surfed the Internet for my project at school.

5. What did her do at the birthday party last week ? Her danced , sang and ate delicous food and drink.

Ex1: Chia động từ trong ngoặc ở thì tương lai đơn hoặc hiện tại đơn
1. But all there things ( happen/only) will happen only . If you marry me.
2. You ( travel ) will travel aroud the world.
3. You ( meet ) will meet lots of interesting people.
4. The sun ( rise ) riese_ over there.
5. Next year, I ( be ) _will be 40 years old.
6. That plane (be) will be late. It alway is.
7. He ( find out ) __will find out_________ possibly when he ( see ) ______sees______ Jenny.
8.Me be it ( be ) _is_OK.
9.I think I ( go ) should ___ go_____ to bed now.
10. I ( not tell ) __don't tell_________ him. I promise.

Reorder the words to make meaningful sentences :

your / must / before / you / homework / school / do / going / to .

-> You must do your homework before going to school.