B4

What's your favourite season? I think mine is spring.

(мой)

I

B5

Birds, singing in the trees, tell us that winter is finally over.

(Participle I, “поющие на деревьях”, подходит по смысловому контексту)

Sing

B6

The animals that have been asleep for months wake up and start to look for food.

(present perfect, т.к. они уже проспали. Это время используется с периодами)

Be

B7

The days are much warmer than they were in the winter, so the plants start to grow, too.

(степень сравнения)

Warm

B8

The countryside looks fresh, beautiful and alive.

(present simple, т.к. это общее утверждение)

Look

B9

We can leave our coats and umbrellas at home when we go out.

(present simple, т.к. это общее утверждение)

Leave

B10

And unlike in the summer, the sun doesn’t burn our skin when we spend a long time outside.

(present simple, т.к. это общее утверждение)

Not burn

B11

The best  thing of all about spring, though, is knowingthat the summer is not far away!

(превосходная степень)

Good