The formation of cis-trans isomers is a consequence of the absence of free rotation. Geometric isomers that only differ from each other in the 3-dimensional arrangement of the substituents in space. They have identical bonding and substituents. Alkane.
What sells out first: Christmas/New Years, Presidents Week in February, Spring Break Week in March, Easter Week and July/August sailings when the children are out of school. To get the space you want on the cruise and necessary air arrangements, don't hesitate to book 9 to 11 months in advance if possible. The remainder of February, March and April sailings usually start to fill up once the weather starts to turn cold in the Northeast and Midwest.
How and when to book a cheap flight. New research shows that the best time to book a summer flight is as late as five weeks before your holiday, contrary to travel industry experts who advise travellers book as early as possible. See also: How to get best holiday deals. Isabel Choat. theguardian.com, Wednesday 22 January 2014 06.00 GMT.