1. The girl is as (tall) as her mum.
2. Be (active) at your lessons, please.
3. The problem was (serious) we expected.
4. My garden is not (big) as theirs. — Правильный ответ на вопрос найдете ниже

Ответ: 1. Tall2. More active3. More serious3. As big

Ответ:

the girl ios as tall as her mum.

be active at your lessons please.

the problem was more sirious then we expected.

my garden is not so big as thers.