Complete the sentences with because or because of.

1. My sister could not reach the destination on time _____ the terrible traffic jam.

2. The final test was so easy _____ Olive knew all the answer.

3. _____ the language barrier, my uncle and my aunt got divorced.

4. All flights to Đà Nẵng were cancelled _____ the harsh climate conditions.

5. _____ Tom’s laziness, he can’t get the high scores in the exam.