My dog ( be ) 20 years old today if it ( be ) alive

Will be, was. По-моему там Conditional

Ну вообще, в некоторых предложениях можно несколько вариантов подставить. Поэтому надо уточнять задание, какие именно времена или типы кондишн использовать.

1) If she visit me, I will be glad.
(или) If she visited me, I would be glad.

2) Tonight I will go to bed after I do my homework.

3) When the lessons finish, the teacher will give us marks.

4) If they come tomorrow, I will make a cake.

5) If you arrive late, you will miss your flight.

6) She will buy me a present if she go to Australia.

7) If you don't climb the tree, you won't see a bird.

8) If the weather doesn't change, the plane won't be on time.

9) We will see Big Ben if we travel to London.

10) If I don't have mistakes, I will get 10 ... (неполный пункт, мне кажется)

Read the text. Use the appropriate forms of the words on the right to complete it.
Sometimes jazz concerts are broadcast on the radio and on television. We(1) are sure that you (2) 've heard about this type of music. It (3) appeared in the United States when the (4) first Africans (5) were brought to North America. In those years many native songs (6) were sung by (7) them and the music of (8) their homeland (9) was played on the new continent.
Modern (10) scientists write that jazz (11) is made up of the music of West Africa.