在往复皮带输送机运行到浸渍器入口过程中，它自己的皮带不转动。
参考答案：错
若（x-ay）（x+ay）=x2-16y2，则a=______．
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
