井底压持效应越小，钻速就越高。
参考答案：对
下列各组物质中互为同位素的是( )
A．和
B．D和T
C．H2O和H2O2
D．O3和O2
These tax laws which are intended for domestic companies do not _____ to foreign companies.
A．contribute
B．lead
C．apply
D．adapt
和
