离子交换树脂的交联度值越大，树脂的视密度越大，抗氧化性能越强。
参考答案：对
Not only ______ to look after her children, but also _____ to work.
A．she had; did she have
B．did she have; she had
C．she had; she had
D．did she have; did she have
Every time Ashtita tries to break a record, he reaches a point ______ he feels he cannot physically do any more.
A．where
B．that
C．when
D．which
