Telomerase is an enzyme that is produced only in cells that are actively dividing. For this reason it is generally absent from body tissues in adults. Bone marrow is an exception to this rule, however, since even in adults, bone marrow cells continually divide to replace old blood cells. Cancers are another exception, because their cells are rapidly dividing.
The information provided most strongly supports which of the following?
Telomerase is the only enzyme that is present in cancerous cells but absent from cells that are not actively dividing.
In children, the only body tissues from which telomerase is absent are those in which cells are not rapidly dividing.
The presence of telomerase in bone marrow is no indication of bone marrow cancer.
Cancer of the bone marrow develops more rapidly than cancer growing in any other kind of adult tissue.
The level of telomerase production is always higher in cancerous tissue than in noncancerous tissue.
B 条件结论型;T只存在于active dividing的cell里。
Only之后的为必要条件,也就是说T能推出active dividing的cell,
没有T不能推出别的,因为不是逆否命题
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