Task 220. It is popularly believed that all research needs ca21. One should make sure the research is____22. It is as difficult to solve a useful problem as to23. One may need some simple equipment to overcome24. Not many people realize that it is difficult to25. Failures in research A. happen very oftenB. worth doingC. do somethingnewD. lose one's patienceE. solve a useless oneF. expensive scientific equipmentG. the major difficulties in research
The third paragraph is mainly about
A、the elements in the sea
B、the weather on the sea
C、the studies of the sea
D、the sound under the sea
A. And much of that may need only to be heated before it is ready to eat.B. Yet sometimes, they may eat the same foods.C. In South America, there is a very poisonous plant.D. You may have eaten some of the food yourself.E. There are hot-dog stands on the islands of Sumatra as well.F. Or you may live in a house.