Exercise 3. Oral exercises on the use of the “introductory it”.

It is	necessary important better right difficult most urgent	to do it. to help the old man. to finish the work at once. to discuss the question. to clear the mysterious matter. to find the lost document.
It's	no use	writing to him. asking him about it. aguing.
It is	certain pleasant to hear	that he will come in time. that he will come in time.

 

* Here "it" is the subject of the principal clause of a complex sentence.