Given a context passage, generate a question from the passage such that its answer is shortest continous span from the passage.
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Question: Today, the Eiffel Tower, which serves an important role in television and radio broadcasts, is considered an architectural wonder. It attracts more visitors than any other paid tourist attraction in the world. The Eiffel Tower was designed by the French engineer and bridge builder Alexandre Gustave Eiffel for the Paris Exposition of 1889. The tower is 300 m high and consists of an open iron framework making it the highest manmade structure in the world at the time. It was almost not built. After being awarded the contract to build the tower, Eiffel discovered that the Exposition Committee would only provide about a quarter of the money needed to construct it. Eiffel himself would have to finance the balance. He thought of a deal that would make him a very rich man. He agreed to independently find the people to fund his tower but he wanted to be the only one to control of the tower and he wanted the profits for twenty years. They agreed. To everyone's surprise, including Eiffel, the tower was paid off in the first year. The deal that Eiffel came up with was probably what saved the tower from destruction. A Committee of Three Hundred was formed and they demanded an end to its building. Many members of the committee said, "They have only put up the framework of this monument, It has no skin." Many sculptors and architects protested , in the name of threatened French art and history, about the useless Eiffel Tower, in the heart of their capital. It is built of iron, which is an inferior material, and a single beam of it is unable to support large stresses. That is why the tower appears over-engineered by today's standards. Though, from this very weakness, its simple beauty can be found. If you look at the tower, the structure of it sort of copies the biological cellular structure of a plant.

Answer: What was the Eiffel Tower originally designed for?

Question: To be a good aquifer, the rock in the aquifer must have good: porosity: small spaces between grains permeability: connections between pores To reach an aquifer, surface water infiltrates downward into the ground through tiny spaces or pores in the rock. The water travels down through the permeable rock until it reaches a layer that does not have pores; this rock is impermeable (Figure 1.1). This impermeable rock layer forms the base of the aquifer. The upper surface where the groundwater reaches is the water table. Groundwater is found beneath the solid surface. Notice that the water table roughly mirrors the slope of the lands surface. A well penetrates the water table. For a groundwater aquifer to contain the same amount of water, the amount of recharge must equal the amount of discharge. What are the likely sources of recharge? What are the likely sources of discharge? What happens to the water table when there is a lot of rainfall? What happens when there is a drought? Although groundwater levels do not rise and fall as rapidly as at the surface, over time the water table will rise during wet periods and fall during droughts. In wet regions, streams are fed by groundwater; the surface of the stream is the top of the water table (Figure 1.2). In dry regions, water seeps down from the stream into the aquifer. These streams are often dry much of the year. Water leaves a groundwater reservoir in streams or springs. People take water from aquifers, too. Groundwater meets the surface in a stream (Figure 1.2) or a spring (Figure 1.3). A spring may be constant, or may only flow at certain times of year. Towns in many locations depend on water from springs. Springs can be an extremely important source of water in locations where surface water is scarce. A well is created by digging or drilling to reach groundwater. It is important for anyone who intends to dig a well to know how deep beneath the surface the water table is. When the water table is close to the surface, wells are a convenient method for extracting water. When the water table is far below the surface, specialized equipment must The top of the stream is the top of the water table. The stream feeds the aquifer. A spring in Croatia bubbles to the surface and feeds the river Cetina. be used to dig a well. Most wells use motorized pumps to bring water to the surface, but some still require people to use a bucket to draw water up (Figure 1.4). An old-fashioned well that uses a bucket drawn up by hand.

Answer: the surface of a stream is

Question: Imatinib induces a durable response in most patients with Philadelphia chromosome-positive chronic myeloid leukemia, but it is currently unclear whether imatinib reduces the leukemic stem cell (LSC) burden, which may be an important step toward enabling safe discontinuation of therapy. In this article, we use mathematical models of BCR-ABL levels to make inferences on the dynamics of LSCs. Patients with at least 1 BCR-ABL transcript measurement on imatinib were included (N = 477). Maximum likelihood methods were used to test 3 potential hypotheses of the dynamics of BCR-ABL transcripts on imatinib therapy: (i) monoexponential, in which there is little, if any, decline in BCR-ABL transcripts; (ii) biexponential, in which patients have a rapid initial decrease in BCR-ABL transcripts followed by a more gradual response; and (iii) triexponential, in which patients first exhibit a biphasic decline but then have a third phase when BCR-ABL transcripts increase rapidly. We found that most patients treated with imatinib exhibit a biphasic decrease in BCR-ABL transcript levels, with a rapid decrease during the first few months of treatment, followed by a more gradual decrease that often continues over many years. We show that the only hypothesis consistent with current data on progenitor cell turnover and with the long-term, gradual decrease in the BCR-ABL levels seen in most patients is that these patients exhibit a continual, gradual reduction of the LSCs. This observation may explain the ability to discontinue imatinib therapy without relapse in some cases.

Answer:
What tyrosine kinase, involved in a Philadelphia- chromosome positive chronic myelogenous leukemia, is the target of Imatinib (Gleevec)?