請依下文回答第 6 題至第 10 題
Bryan G can’t eat enough food to make himself grow. Poor nutrition makes him so tired he has no strength to play
ball or walk through an airport without a wheelchair. Bryan suffers from severe, chronic Crohn’s disease. Parts of his
small intestine, usually half an inch 6 diameter, are so diseased they are only as wide as a piece of pencil lead.
For Crohn’s victims, it is nearly impossible to digest and process food. Bryan’s disease is so severe he has recently
been 7 to receive a rare, experimental stem cell transplant. Stem cells are a basic kind of cell. They 8 the
growth of more specific cells. Early experiments indicate that human organs and tissues can be grown from stem cells.
The existence of stem cells was first recognized in the 1900s. European scientists realized that all kinds of blood cells,
including red, white, and T cells, come from one kind of basic cell, the stem cell. In fact, most adult tissue contains
some stem cells in it, 9 when tissue is injured, new cells can be generated. In 1998, researchers isolated and
grew stem cells. Such cells were capable of growing for a long time and differentiating into many kinds of cells.
Stem cells used in research and surgery usually come from human embryos. Stem cells can be grown from adult tissue,
but these stem cells do not seem to last for long, 10 develop into a wide variety of cell types. Thus most of the
stem cells in use for research come from embryos or fetuses.
【題組】10 (A) nor they can (B) nor can they (C) so they can (D) so can they
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