The passage is mainly concerned with ----.

By the end of the twentieth century, East Asia had become
a centre of industrial and manufacturing production.
Especially China began to establish commercial ties with
the West in the 1970s and became the world's leading
heavy industrial producer by the year 2000. Its stateowned
companies acquired contracts from Western firms
to produce products cheaply and in bulk, for sale back to
home markets in the United States and Europe. Moreover,
the Chinese government established semicapitalist
commercial zones around major port cities like Shanghai.
These commercial zones were intended to encourage
massive foreign investment on terms that left China a
favourable balance of trade for its huge volume of cheap
exports. Yet, in practice, they enjoyed only mixed success.
Problems in farming and a looming energy crisis
hampered prosperity and economic growth, but Hong
Kong only managed to maintain its traditional economic
and cultural ties with the rest of the world. However, in
recent years, China has overcome most of these
problems and radically upgraded its economic
performance.