quy ước gen: A- lúa chín sớm

                       a- lúa chín muộn

Vì lai 2 giống lúa thuần chủng chín sớm với chín muộn

Sơ đồ lai:

P: AA( lúa chín sớm) x aa( lúa chín muộn)

G: A                              a

F1: Aa( 100% lúa chín sớm)

b,Cho lai F1 với lúa chín muộn

Sơ đồ lai:

P: Aa( lúa chín sớm) x aa( lúa chín muộn)

G: A,a                             a

F1: 1 Aa:1aa( 1 lúa chín sớm : 1 lúa chín muộn)

c,lai F1 với lúa chín sớm (tc).

Sơ đồ lai:

P: Aa ( lúa chín sớm)  x AA( lúa chín sớm)

G: A,a                              A

F1: 1 Aa: 1 AA 

C.5'...TAA-XTT-GGA-XGG...3'

41. We often go to the town cultural house. We can enjoy and take part in many performances there. (where)

42. We couldn’t get tickets for the football match. We queued for an hour. (in spite of)

43. Nikki is not at school today. Nikki’s turn is to pass out papers. (whose)

44. The brown squirrel ran up the tree. The dog did not bark. (but)

45. No one was at home. The thieves robbed the house. (because)

46. The last time we went to Ho Chi Minh City was in 2009.

=>We haven’t

47. I advise you to be more truthful in future.

=>If I

48. “Let’s have a pinic next Sunday,” Maria said.

=>Maria suggested

49. People believe that the wanted man is living in New York.

=>The wanted man

50. We didn’t have enough money to buy the picture.

=>The picture was too