be positive of/about...确信......，肯定......

　　be positive about...乐观的/积极的

　　a positive result良好的结果

　　to have a good/bad/positive/negative attitude towards sb./sth.对某人(或事物)持好的/坏的/肯定的/否定的态度

　　完成句子

　　(1)Are_you_positive(你确定)that there's been no mistake?

　　(2)Students learn better in_this_positive environment(在这样良好的环境中)．

　　(3)You have every reason to be_positive_about_the_future(对未来感到乐观)．

　　5

　　His friends were enthusiastic and encouraged him to publish his ideas，but Copernicus was cautious.他的朋友都热情地鼓励他把他的想法公诸于世，而他却小心谨慎。(回归课本)

　　用法点拨

　　He is very enthusiastic about the plan.

　　他对这项计划十分热心。

　　My parents are enthusiastic skiers.

　　我的父母是滑雪迷。

　　归纳拓展

　　be enthusiastic for/about sth.对某事热心

　　enthusiastically adv.热情地

　　enthusiasm n．热心，热情；狂热；后面常加for

　　enthusiast n．热衷者，热心者

　　佳句背诵

　　(1)For a while，we were enthusiastic about the idea.

　　我们曾一度对这个想法很感兴趣。

　　(2)His enthusiasm for music has stayed strong throughout his 23 years in radio.

　　在整整23年的电台生涯里，他一直酷爱着音乐。

　　(3)Business leaders gave an enthusiastic welcome to the proposal.

　　商界领袖热烈欢迎这项提议。

　　6

　　...，but Copernicus was cautious.但哥白尼却小心谨慎。(回归课本)

　　用法点拨

　　He was cautious when he was riding the bicycle.

　　他骑自行车的时候很小心。

　　Companies seem cautious about investing money in research and development.

　　公司在研究开发方面的投资似乎比较谨慎。

　　She approached the horse cautiously.

　　她小心翼翼地靠近那匹马。

　　归纳拓展

　　be cautious about对......谨慎

　　caution n．小心，谨慎

　　with caution小心地

cautiously adv.小心地，谨慎地