Over almost all of Oklahoma, winter is the driest season. Average monthly precipitation increases dramatically in the spring to a peak in May, the wettest month over most of the state, with its frequent and not uncommonly severe thunderstorm activity. Early June can still be wet, but most years see a marked decrease in rainfall during June and early July. Mid-summer (July and August) represents a secondary dry season over much of Oklahoma, with long stretches of hot weather with only sporadic thunderstorm activity not uncommon many years. Severe drought is common in the hottest summers, such as those of 1934, 1954, 1980 and 2011, all of which featured weeks on end of virtual rainlessness and high temperatures well over 100 °F (38 °C). Average precipitation rises again from September to mid-October, representing a secondary wetter season, then declines from late October through December.
What years were Oklahoma's hottest summers?
1934, 1954, 1980 and 2011

The evolution of seed plants and later angiosperms appears to be the result of two distinct rounds of whole genome duplication events. These occurred at 319 million years ago and 192 million years ago. Another possible whole genome duplication event at 160 million years ago perhaps created the ancestral line that led to all modern flowering plants. That event was studied by sequencing the genome of an ancient flowering plant, Amborella trichopoda, and directly addresses Darwin's "abominable mystery."
How many distinct rounds of genome duplication events are suspected in the evolution of seed plants?
two

The city also has several major surface arteries. U.S. Route 1 (Columbus Avenue, Union Avenue, Water Street, Forbes Avenue) runs in an east-west direction south of downtown serving Union Station and leading out of the city to Milford, West Haven, East Haven and Branford. The main road from downtown heading northwest is Whalley Avenue (partly signed as Route 10 and Route 63) leading to Westville and Woodbridge. Heading north towards Hamden, there are two major thoroughfares, Dixwell Avenue and Whitney Avenue. To the northeast are Middletown Avenue (Route 17), which leads to the Montowese section of North Haven, and Foxon Boulevard (Route 80), which leads to the Foxon section of East Haven and to the town of North Branford. To the west is Route 34, which leads to the city of Derby. Other major intracity arteries are Ella Grasso Boulevard (Route 10) west of downtown, and College Street, Temple Street, Church Street, Elm Street, and Grove Street in the downtown area.
What east-west artery in New Haven serves Union Station?
U.S. Route 1