Tom is          good a student        he is often praised by the teacher.

You can get the best result ______you carry out the experiment under the desired conditions.

________ a child begins school, he enters a world of vicious competition where success and failure are clearly defined and measured.

________ many countries in Latin America have been trying to reduce gaps in income, America has allowed inequality to grow.

_________ the internet is _________, I do not think it is a good idea to spend too much time on it.