浮动覆盖常用的覆盖材料主要有（）、（）等。采用浮动覆盖可使温度提高（）。
参考答案：不织布；遮阳网；1~3℃
再生障碍性贫血一般不伴有肝脾肿大。
—Look! The telephone is broken. Someone damaged it purpose.
—That may be right. But perhaps it was broken accident.
A．on; by
B．by; by
C．on; on
D．by; on
