Question

1.     Margaret stayed at home because her mother was sick.

 Owing to

2     I couldn’t do the test because it is difficult.

Due to

 

Answer 1

1.     Margaret stayed at home because her mother was sick.

 Owing to her mother's sickness, Margaret stayed at home

2     I couldn’t do the test because it is difficult.

Due to the difficulty of the test, I couldn't do it