多层建筑内的电缆井、管道井应在每层楼板处采用（）楼板耐火极限的不燃烧体封堵。A、低于

特异性高，效价随SLE病情缓解而下降

A．抗核抗体
B．抗Sm抗体
C．抗双链DNA抗体
D．抗磷脂抗体
E．类风湿因子

银州贸易城果品批发市场运来7000千克水果，几个个体经营者买去250箱，还剩750千克．每箱水果有多少千克？（列方程解答）

用所给词的适当形式填空。

1. A year _________(divide) into 12 star signs.

2. The first _________(clone) sheep was named Dolly.

3. Stop _________(argue) about it. Let's be friends again.

4. The _________(relax) music made us even _________(relax).

5. Amy has just had his bicycle _________(repair).

6. It's a good _________(choose) to _________(choose) him as our monitor.

7. It's much _________(sun) today than yesterday.

8. _________(eat) too much is _________(health) for our health.

9. Your advice will be of great _________(valuable) to us.

10. I _________(colour) the card orange _________(cheer) you up and it brought you joy.

气孔减少了铸件的有效面积，造成局部（），降低了铸件的力学性能。