The following chapters provide step-by-step instructions for practical _______ of genetic (基因)engineering to agriculture.
I know a little bit about the city as I __________ there for one year in my youth.
While working in the countryside, the students a great deal of knowledge on plant life.
Criticism and self-criticism _____ necessary _____ it helps us to correct mistakes.
Running a company is not _______ a matter of hiring people — they also need to be trained.
—What made ber so sad? —______a good chance to go abroad.