31. | Some previous knowledge of chemistry is necessary . |
| 必须预先有一点化学知识。
|
32. | No alterations should be made unless absolute necessary . |
| 除非绝对必要,否则不要作任何改动。
|
33. | Decision is necessary for a commander. |
| 果断对于指挥员来说是必不可少的。
|
34. | It is necessary to the future of the country. |
| 这对国家的未来是必要的。
|
35. | Sleep is necessary to health. |
| 睡眠岁健康是必要的。
|
36. | A good trade name is necessary for a commercial product. |
| 商品必须有个好的商标名称。
|
37. | an indispensable [a necessary ] preliminary to sth. |
| 某事开始前必需的一步。
|
38. | Much office work is not directly productive, even if it is necessary . |
| 大量的办公室工作即使必要也是非直接生产性的。
|
39. | There is a provision for making the rebuilding larger if necessary . |
| 有在必要时可以扩建大楼的准备。
|
40. | She has money to make necessary purchases. |
| 她有钱购买必需品。
|