2. In China, gas compressor manufacturing industry has experienced a rapid increase within these years.

6.The gas compressor manufacturing industry has been well-developed in China, and heated competition

The price of gas has greatly (increase) __________ in recent years.

China's space industry has witnessed rapid progress ___ 2011

The country has experienced a population increase in the past 20 years. (替换划线部分词汇)

A、

accretion

navigation

alleviation

immigration