Jawaban:

1.

- It was such a difficult test that the students weren't able to do it.

- The test was so difficult that the students weren't able to do it.

2.

- The cheese cake is so delicious that my mother makes it every day.

- It is such a delicious cake that my mother makes it every day.

3.

- The box is so big that the girl left it at home.

- it is such a big box that the girl left it at home.

4.

- The computer is so old that it lags every time I use it.

- It is such an old computer that it lags every time I use it.

5.

- My father's car is so fast that he never comes late to his office.

- It is such a fast car that my father never comes late to his office.