121. 左右为难 Between the devil and the deep blue sea
122. 众口难调 It's hard to please all tastes.
123. 种瓜得瓜，种豆得豆 As you sow, so shall you reap.
124. 重赏之下，必有勇夫 Where there's a will, there's a way.
125. 知己知彼，百战不殆 Know yourself and know your enemy, and you can fight a hundred battles with no danger of defeat.
126. 竹篮打水一场空 Trying to catch water in a bamboo basket.
127. 坐井观天 Seeing only a small part of the sky.
128. 坐山观虎斗 Watching a fight from the sidelines.
129. 走马观花 Glancing over things hastily.
130. 指鹿为马 Confusing black and white.
131. 知人知面不知心 You can know a person's face but not their heart.
132. 知之为知之，不知为不知 To know what you know and what you do not know, that is true knowledge.
133. 只可意会，不可言传 Can be understood but not expressed in words.
134. 只许州官放火，不许百姓点灯 Allowing the powerful to do as they please while restricting the common people.
135. 只见树木，不见森林 Can't see the forest for the trees.
136. 只缘身在此山中 Because I am in the midst of it, I cannot see it clearly.
137. 纸老虎 A paper tiger.
138. 自古英雄出少年 Great men are seen in the youth.
139. 自力更生，艰苦奋斗 Self-reliance and hard work.
140. 自相矛盾 A contradiction in terms.