One of the most important questions they had to consider was of public health.
The old man often looked back on the past days ________ he worked hard to make a living.
Recently I have bought an iPad 3 on the website of taobao. com, ________ the price is very reasonable.
Have you ever seen any trees ________ leaves were black because of the polluted air?
The scientist won the Nobel Prize in Chemistry, ________ made him famous all over the world.
The result was not the same ________ the professor had expected, ________ was rather disappointing.