某化学兴趣小组为测定Fe、Cu、Ag三种金属的活动性顺序设计了四种方案,每种方案所需试剂如下,你认为不可行的是
One of the most important questions they had to consider was _____ of public health.
Encourage your children to try new things, but try not to ___ them too hard.
The computer was used in teaching. As a result, not only__________, but students became more interested in the lessons.
The children all turned ____ the famous actress as she entered the classroom.
Edward, you play so well. But I ______ you played the piano.