Mulan told me her class had begun studying frogs.

穆兰告诉我，在课堂上，已开始学习有关青蛙的知识了。

youdao

When he got school, the first class had begun.

他到校时，第一节课已经开始了。

youdao

Arriving at the school, we found that class had begun.

我们赶到学校时，发现已经开始上课了。

youdao

The bank, under the guidance of its top executives, Ferozi and Sherkhan Farnood, a world-class poker player, had begun to founder, in part owing to the collapse of the property market in Dubai.

NEWYORKER: The Afghan Bank Heist

Class-action suits for negligence had begun in three provinces.

ECONOMIST: Canada

By then, however, the class had lost much of its early momentum and begun to adjust to the customs and priorities of the House.

CNN: By Ronald D. Elving, CQ Staff Writer