监督网络应按厂级技术监督管理办法或金属及锅炉压力容器管理制度的规定定期开展网络活动，但不用建立相应的记录（）
参考答案：错
The population of this city, 30% of which_______, ______ 10% in the last two years.
A．are Chinese; has risen by
B．are China; has fallen by
C．is Chinese ; have increased
D．is China; have reduced by
