The values of a, d and n are: 1  a = 1 (the first term) 2  d = 3 (the common difference between terms) 3  n = 10 (how many terms to add up)
Five planets will align in the predawn sky tomorrow, awakening Titans and office workers alike. Gulp. It must be time to unleash the Titans: five of the planets in our Solar System will align diagonally in the predawn night sky starting tomorrow morning. Mercury, Venus, Mars, Jupiter, and Saturn will all be visible with the naked eye starting January 20th and lasting until about February 20th. The last time a planetary party like this happened was in 2005. It's also slated to happen again later this year in August.
The future perfect is a verb form or construction used to describe an event that is expected or planned to happen before a time of reference in the future, such as will have finished in the English sentence I will have finished by tomorrow..he future perfect is used to say that something will happen in the future, but before the time of the main sentence. It is called futuro anteriore and is formed by using the appropriate auxiliary verb to be (essere) or to have (avere) in the future simple tense followed by the past participle. For example: