双顶径和头围有什么区别

BEIJING, July 30 (Xinhua) -- The Chinese and Russian navies will hold a joint exercise in the sea and air spaces near Vladivostok, Russia, in August, said Zhang Xiaogang, spokesperson for the Ministry of National Defense.

Following the exercise, some participating forces from both sides will conduct the sixth joint maritime patrol between the Chinese and Russian navies in the Pacific Ocean, Zhang said at a press conference on Wednesday.

The program is part of the annual cooperation plan between the Chinese and Russian militaries, is not directed at any third party, and is unrelated to the current international and regional situation, according to the spokesperson.