整理笔记，发现两个疑点，大家进来看看

以下是引用gemj在2003-11-7 2:35:00的发言：
which修饰的可以是N1
There are at least two classes of these receptors, which have been designated A1 and A2.

T. H. Huxley reasoned that flying vertebrates must have been warm-blooded because flying implies a high rate of metabolism, which in turn implies a high internal temperature.

which修饰的也可以N2

This truth was not apparent to managers of one regional bank, which failed to improve its competitive position despite its investment in reducing the time a customer had to wait for a teller.

The advent of private hospital health insurance, which provided middle-class patients with the purchasing power to pay for private hospital services, guaranteed the private hospital a regular source of income.