In this task, you are given a question and a context passage. You have to answer the question based on the given passage.
--------
Question: What needs consistency?, Context: The simplest valve gears give events of fixed length during the engine cycle and often make the engine rotate in only one direction. Most however have a reversing mechanism which additionally can provide means for saving steam as speed and momentum are gained by gradually "shortening the cutoff" or rather, shortening the admission event; this in turn proportionately lengthens the expansion period. However, as one and the same valve usually controls both steam flows, a short cutoff at admission adversely affects the exhaust and compression periods which should ideally always be kept fairly constant; if the exhaust event is too brief, the totality of the exhaust steam cannot evacuate the cylinder, choking it and giving excessive compression ("kick back").[citation needed]

Answer: exhaust and compression periods


Question: What are the internal layer of pouches on an etioplast called?, Context: If angiosperm shoots are not exposed to the required light for chloroplast formation, proplastids may develop into an etioplast stage before becoming chloroplasts. An etioplast is a plastid that lacks chlorophyll, and has inner membrane invaginations that form a lattice of tubes in their stroma, called a prolamellar body. While etioplasts lack chlorophyll, they have a yellow chlorophyll precursor stocked. Within a few minutes of light exposure, the prolamellar body begins to reorganize into stacks of thylakoids, and chlorophyll starts to be produced. This process, where the etioplast becomes a chloroplast, takes several hours. Gymnosperms do not require light to form chloroplasts.

Answer: invaginations


Question: While where did she do something no one in her position had done before?, Context: Victoria visited mainland Europe regularly for holidays. In 1889, during a stay in Biarritz, she became the first reigning monarch from Britain to set foot in Spain when she crossed the border for a brief visit. By April 1900, the Boer War was so unpopular in mainland Europe that her annual trip to France seemed inadvisable. Instead, the Queen went to Ireland for the first time since 1861, in part to acknowledge the contribution of Irish regiments to the South African war. In July, her second son Alfred ("Affie") died; "Oh, God! My poor darling Affie gone too", she wrote in her journal. "It is a horrible year, nothing but sadness & horrors of one kind & another."

Answer:
Biarritz