It is not clear what it will be able to do to help revive energy talks with Uzbekistan, Kazakhstan and Turkmenistan, During negotiations in the Czech capital,Prague, the three natural-gas producing nations were not convinced by E.U.offers of more trade and stronger transport links in exchange for their participation in a multi-billion-dollar gas pipeline, known as Nabucco.

VOA: standard.2009.05.11

This restriction enzyme was found in a natural source, it was found in a micro-organism called E.coli.

这个限制性内切酶源于自然界,是从名为大肠杆菌的微生物中发现的

耶鲁公开课 - 生物医学工程探索课程节选

e This is just base e, natural logarithm.

减去EXP自然对数中的。

麻省理工公开课 - 固态化学导论课程节选