关于绿色植物在生物圈中作用的说法，正确的是（　　）

已知各项皆为正数的等比数列{a_n}（n∈N^*），满足a₇=a₆+2a₅，若存在两项a_m、a_n使得$\sqrt{a_m{a}_n}=4a_1$，则$\frac{1}{m}+\frac{4}{n}$的最小值为____ 

设a，b为互不相等的正实数，求证：4（a³+b³）＞（a+b）³．

    While ____ (visit) Hangzhou's West Lake and its surrounding beautiful hills, you'll understand ____ it's been a great source of inspiration（灵感）for artists,poets and philosophers throughout Chinese history.

    Though ____ rest of the country is moving from two wheels to four,cycling culture is thriving（繁荣的）in Hangzhou. The city ____ (develop) China's first bike-sharing system in 2008.Since then,it's grown into the world's ____ (big) and one of the world's best public bike systems.

    Hangzhou grows some of China's finest green tea—Longjing.Every spring,before the traditional Qingming Festival, tea ____ (love) from all over the country come to Longjing, a village ____ lies just south of West Lake,for the first cut of top-quality tea. During tea season— ____ (usual) late March and April—the air is filled with smell from the tea, when leaves ____ (pick) and roasted in the village.The village is open to the public and you can pick your own tea after getting ____ (permit) from the local tea farmers.