A shoal of fish will do this.

鱼群也反射声音。

It did not, however, remain within the confines of his estate.

然而，这种疾病并未被局限在他的庄园内，

It is said that the nerve poison is the more primitive of the two, that the blood poison is, so to speak, a newer product from an improved formula.

据说，神经毒液在两种毒液中是较为原始的一种，而溶血性毒液，打个比方说，是根据改良配方生产的一种较新的产品。

not to mention the equally numerous small animals like field mice and voles which you do not see,

地上有不显眼的无数的老鼠和田鼠之类的小动物，

Such a loss of dignity and descent into childish behaviour on the part of the adults deeply shocks the adolescents,

这种有失身份和孩子气的作法使青春期的孩子大为震惊，

and a very firm hand must be employed in the early stages.

因此开始阶段需要有一位强有力的老手。