This book _____ ten units, ______ three mainly revision.
.This old computer must have been of great use to ____________ did the scientific research.
..It was _______ he said that _______ me feeling frustrated.
.__________I am amazed at is__________she wants to find fault with others all the time.
.—Is it OK if I have another cup of coffee?—Of course, _______.
.A terrible accident _______,however, occur the other day and we caught sight of it _______ accident.