Only through a lot of practice           such skills and experience. 

---Is everyone here?---Not yet, look, there _____ the rest of the students.

There is a real possibility that these animals could be frightened, ________ a sudden loud noise.

____ in a branch of the tree ___ a note which read "I'll meet you at the School Gate".

Not until the train pulled into the station          that his suitcase was gone.