Since pure foaming agent with short half-value period causes a poor plugging effect for high-permeability reservoir with water channeling, this paper studies on gel foam sysem.
Shares were trading at under half their usual value.
那些股份以低于通常价值的一半买卖。
《牛津词典》
3
After running hundreds of tests, the researchers noted that the monkeys would go for the higher values more than half the time, indicating that they were performing a calculation, not just memorizing the value of each combination.