But in 1960, many experts believed that the placental barrier shielded a fetus from harm.

但在 1960 年，许多专家认为胎盘屏障可以保护胎儿免受伤害。

But the attack was trained, too, and conditioned by the necessities of penetrating a shield barrier.

但这次攻击也是经过训练的，并且以穿透盾牌屏障的必要性为条件。

Paul thought of the storm sweeping across the basin, the static charge within the wall of sand that destroyed every shield barrier in the enemy camp.

保罗想起席卷盆地的暴风雨， 沙墙内的静电荷摧毁了敌营中的每一个盾牌屏障。