丙烯颜料干燥后是（）的，是室外或在棉布上绘画的理想材料。
A.防水
B.防尘
C.抗损
D.防腐蚀
参考答案：A
_____ in his test papers，he didn't notice my coming. [ ]
A. Having absorbed
B. Absorbed
C. Absorbing
D. Being absorbed
何为惰走？惰走时间？惰走曲线？
