多选：粉煤灰水泥的特性主要是（ ）。A．水化热较小B．抗冻性好C．抗裂性较高D．耐蚀性较好

Which of the following shows the correct sentence stress in normal cases

下面谱例中的旋律片段出自哪首乐曲？（）A．《雨打芭蕉》B．《姑苏行》C．《彩云追月》D．《旱天雷》

When teaching students how to give appropriate responses to a congratulation ...

Walnut trees __________ environment stresses such as drought by producing sig...

The professor′s classroom manner was quite__________，never revealing the warm...