There have been large-scale military manoeuvres on the frontier.

边曾有过大规模的军事演习。

This happened in the center of operations.

这事发生在演习的过程中。

The fleet is maneuvring off the east coast.

舰队正在东海外演习。

The fleet is -ring off the east coast.

舰队驶离东海进行演习。

The drilling troops mustered on the hill.

演习部队在小山集合起来了。

Military planes flew over the country in a warlike action.

军用飞机在进行军事演习时从该国空飞过。