单选题
The animal dissection requirement of biology classes has been getting under the skin of students for generations, and there have always been some who asked to be excused from the requirement. Now, a growing number of technological alternatives are making it possible for students to swap that scalpel for a computer mouse. There are laws in nearly a dozen states — including California, Florida, New York — protecting a student's choice to learn about animal anatomy sans scalpel. Some students choosing to opt out feel we should be kinder to our web-footed friends. Others are just queasy at the thought of rubbery frog bodies and the smell of formaldehyde. Dissection is icy. There's a yuck factor. " admits Brian Shmaersky, a boared member with the National Association of Biology Teachers. " And a teacher has to weigh the benefits with the cost of students being offended to the point that it interferes with learning. " Virtual blades. So for cases in which a real dissection would be too slimy, it's time to try some toad tech. While the first computer-based alternatives to dissection emerged in the 1980s, modern frog dissection software can be found at different websites. These software programs use creative clicking, high-powered zoom functions, and video clips to teach anatomy. Froguts software, for example, lets students trace incision lines with a computer mouse and snip through skin with a virtual blade. There are even sound effects like a "slish" for slicing frog flesh, or a "shwoosh" for pinning down skin flaps.(Schools currently pay about $ 300 for a one-year software license, though some organizations will lend programs out free of charge.) Earlier this year, a graduate student from Simon Fraser University in Vancouver designed the first-ever haptic(the Greek word for "touch")frog dissection program, which uses a penlike tool to create a sensation similar to cutting into real flesh. The hand-held device connects to a computer, and students move the device through the air while watching the results of their actions on a computer screen. With Digital Frog — a popular program that's had approximately 1, 500 frog demo downloads since January and is currently in use in 2, 000 schools — students can add or subtract those amphibious organs with a mere mouse click. They can then assess their learning with sporadic frog anatomy quizzes. "Repetition is helpful. The fact that a student can review sections of a program over and over again is important," says Martin Stephens, vice president for animal research issues at the Humane Society of the United States. "In dissections, the animal's organs are all shriveled and discolored. You look for things and can't find them because body parts have changed drastically since the animal was killed. But on a computer screen, layers can be digitally peeled away. " Other experts think the dissection technology has its limits. Gerry Wheeler, executive director of the National Science Teachers Association, says that artificial simulations don't give as enriching an experience as the real thing. Still others worry the programs are depriving kids of experiential learning.
单选题
The word "swap"(Line 4, Paragraph 1)most probably means______.