英语语法分析

Vietcong numbers smoothly kept pace, despite losses estimated at 60,000 a year.

而越共数量虽然一年损失60,000，却平稳保持同美军一致。

But it quickly became clear that US airpower alone was doing little to halt Vietcong operations in the south.

但是很快事情变得明朗，美军仅仅开展轰炸几乎不能阻止越共在南越的军事行动。

The military condition deteriorated, and by 1963 South Vietnam had lost the fertile Mekong Delta to the Vietcong.

军事形势不断恶化，到1963年南越失去了肥沃的湄公河三角洲。