Input: Read this: In the diffuse-porous woods, the demarcation between rings is not always so clear and in some cases is almost (if not entirely) invisible to the unaided eye. Conversely, when there is a clear demarcation there may not be a noticeable difference in structure within the growth ring.
Question: In diffuse-porous woods, if the demarcation between rings is obvious, what type of difference within the ring might not be?

Output: structure


Input: Read this: The dominant northern and high elevation conifer is the red spruce (Picea rubens), which grows from near sea level to above 4,000 ft (1,200 m) above sea level (asl) in northern New England and southeastern Canada. It also grows southward along the Appalachian crest to the highest elevations of the southern Appalachians, as in North Carolina and Tennessee. In the central Appalachians it is usually confined above 3,000 ft (900 m) asl, except for a few cold valleys in which it reaches lower elevations. In the southern Appalachians it is restricted to higher elevations. Another species is the black spruce (Picea mariana), which extends farthest north of any conifer in North America, is found at high elevations in the northern Appalachians, and in bogs as far south as Pennsylvania.
Question: How far south can red spruces be found?

Output: unanswerable


Input: Read this: On June 22, 1990, Volodymyr Ivashko withdrew his candidacy for leader of the Communist Party of Ukraine in view of his new position in parliament. Stanislav Hurenko was elected first secretary of the CPU. On July 11, Ivashko resigned from his post as chairman of the Ukrainian Parliament after he was elected deputy general secretary of the Communist Party of the Soviet Union. The Parliament accepted the resignation a week later, on July 18. On July 16 Parliament overwhelmingly approved the Declaration on State Sovereignty of Ukraine - with a vote of 355 in favour and four against. The people's deputies voted 339 to 5 to proclaim July 16 a Ukrainian national holiday.
Question: How long did it take Parliament to accept Ivashko's resignation?

Output: a week


Input: Read this: To allow for greater movement while dancing and singing, Madonna was one of the earliest adopters of hands-free radio-frequency headset microphones, with the headset fastened over the ears or the top of the head, and the microphone capsule on a boom arm that extended to the mouth. Because of her prominent usage, the microphone design came to be known as the "Madonna mic". Metz noted that Madonna represents a paradox as she is often perceived as living her whole life as a performance. While her big-screen performances are panned, her live performances are critical successes. Madonna was the first artist to have her concert tours as reenactment of her music videos. Author Elin Diamond explained that reciprocally, the fact that images from Madonna's videos can be recreated in a live setting enhances the realism of the original videos. Thus her live performances have become the means by which mediatized representations are naturalized. Taraborrelli said that encompassing multimedia, latest technology and sound systems, Madonna's concerts and live performances are deemed as "extravagant show piece, a walking art show."
Question: What did Madonna use in her concerts?

Output:
hands-free radio-frequency headset microphones