All of us must remember that we are here to add_________ we can to life, not to get _________ we want from it.
The dam will generate electricity _____ about 40 million tons of coal without causing so much air pollution.
Mencius believed that the reason why man _____ the animals is that man is good.
Strong sandstorms are often _____ you cannot see the sun.
He then moved to London, _____ he became famous.
One third of the class _____ agreed to be volunteers to help the aged this vocation.