She tried to finish her homework ________ she was tired.

Rice is (1)______ by Vietnamese people every day. It often (2)______ in tropical countries such as Vietnam, Thailand or Malaysia. The Chinese have also been growing rice for (3)______ years. The seeds are planted in special beds to grow into young rice plants. Then they are taken to fields covered (4)______ muddy water called paddies. The fields of rice look very (5)______. After 3 or 5 months, the rice is ready to be picked. People often drain away water before colleting rice. Eating rice is a special action in the world. They don’t (6)______ spoons or forks to enjoy bowls of rice. Instead, they use two short sticks known as chopsticks to put rice into their mouths. China and Vietnam are the two countries in which people use chopsticks very well.

(1)

Many people still believe that natural resources will never be end up. Actually, the world’s energy resources are limited. Nobody knows exactly how much fuel is left. However, we also should save them economically and try to find out alternative sources of power. According to Proffessor Marvin Burnham of the New England Institute of Technology, we have to start conserving coal, oil and gas before it is too late; and nuclear power is the only alternative. However, many people do not approve of using nuclear power because it is very dangerous. What would happen if there was a serious nuclear accident? Radioactivity causes cancer and may badly affect the future generation.

The most effective thing is that we should use natural resources as economical as possible.

Natural resources will never be end up.

I can’t go there with you because I am busy now. (Rewrite the sentence, using “ If”.)

If I were ___________________________________________________________