A swarthy boy opened a book and propped it nimbly under the breastwork of his satchel.

一个面色黧黑的少年打开本，麻利地将它支这座胸墙底下。

In the angle at the left of this epaulement,there was visible the head of the column of a battalion from the suburbs massed in the Rue Saint-Denis.

胸墙左角，我们可以看到集合圣德街上的一营郊区军队前面几排的士兵。