When we use more than one example in our writing, we can arrange the example in ______, _____, and _____. ( )
现在人们利用藻类植物生产生物燃料，这是利用藻类的哪一主要特征。（）
84 党的十七大首次提出“生态文明”概念，生态文明的基本涵义是 A生态意识文明 B生态制度文明 C生态
Which of the following sentence patterns can be used to draw difference? ( )
生态文明的核心是坚持经济发展与自然的和谐共生。
Which of the following words can signal emphasis to show what is said is important. ( )
清新空气的负氧离子含量为每立方厘米空气中不低于（)。
In what ways can signal words be a valuable aid?( )
生态学是研究______的科学。A．生物之间相互作用相互影响B．生物与环境之间相互作用相互影响C．生物
What are the basic steps of introducing a business idea? ( )
Examples are usually introduced by the following words and phrases except _____.
20世纪著名的环境公害事件—伦敦烟雾事件、马斯河谷烟雾事件和多诺拉烟雾事件等，就是典型的（ ） 污染。
It is a _________ to say you support him but would not vote for him in the election. ( )
我国人工林面积世界第一，这是非常伟大的成绩。塞罕坝成功营造起百万亩人工林海，创造了世界生
Which of the following sentences is asserting an opinion.
