139. There is no denying that the qualities of our living have gone from bad to worse.
140. It is universally acknowledged that trees are indispensable to us.
141. There is no doubt that our educational system leaves something to be desired.
142. An advantage of using the solar energy is that it won't create any pollution.
143. The reason why we have to grow trees is that they can supply fresh air for us.
144. So precious is time that we can't afford to waste it.
145. Rich as our country is, the qualities of our living are by no means satisfactory.
146. The harder you work, the more progress you make.
147. The more books we read, the more learned we become.
148. To average people, they often tend to live under the illusion that English often means a good opportunity for one's career, is this really the case?
149. By taking exercise, we can always stay healthy.
150. Listening to music enables us to feel relaxed.
