The sun ___ we get heat and light is the most important source of energy.
________ he has limited technical knowledge, the old worker has a lot of experience.
The village has developed a lot ________ we learned farming two years ago.
—Where's that report?—I brought it to you ________ you were in Mr.Black's office yesterday.
Many of them turned a deaf ear to his advice,________ they knew it to be valuable.
A man cannot smile like a child,________ a child smiles with his eyes,while a man smiles with his lips alone.