锚固点
参考答案：
管道温度变化时，直埋直线管道产生热位移管段和不产生热位移管段的自然分界点。
．To deal with the global financial crisis, China ______ the international community to help developing countries．
A．called on
B．called up
C．called in
D．called for
We should be able to do the job for you quickly, ____you give us all the necessary information.
A．in case
B．so long as
C．if only
D．as far as
