–Why has Tom looked unhappy recently? –He has some difficulty ______ with his new classmates at school.

I was late for school this morning because the traffic was _________ by an accident.

 ------ Bob failed in the exam again . ------ He _____  it ; he never worked hard .

Do you know how much time and effort they devoted___________such a complicated project ? 

It ___ to me that she didn’t know I had moved into the new house.