题目内容
木材按照材料的不同木材可分为( )?
查看答案
搜索结果不匹配？点我反馈
更多问题
木材的构造可分为（）与（）？
木材构造决定着木材的实用性与装饰性
材横断面上的同心环，称之为髓线
[音频]BananasRecently, some concerns have been ___1____ about the health of the world's banana plants. A number of __2_____reports have said that bananas may _____3_______ disappear. Some ___4____ that this could happen in as little as ten years.Bananas are one of the world’s most important food____5___. They are also the fourth most____6_____ export. Bananas do not grow from seeds. Instead, they grow from existing plants. Bananas are _____7______ by disease because all the plants on a farm are __8____ of each other. They all share the same genetic weaknesses.The International Network for the Improvement of Banana and Plantain supports ____9_____ on bananas. The group has ______10________ in France and other offices in the major banana- growing areas of the world. The group says that more research must be done to develop ___11______ kinds of bananas.The UN agency says farmers should grow different kinds of bananas. This __12______ against diseases that __13____ only one kind. Experts warn that disease may cause the Cavendish banana to disappear. This has already ___14_______ to one popular banana because of its genetic weakness against disease.
微信支付 
支付宝支付