金属在高温和应力作用下逐渐产生（）的现象叫（）。
参考答案：塑性变形；蠕变
— Where is the panda?
— It __________ by the doctor now.
A．was being examined
B．is being examined
C．will be examined
D．has been examined
中 * * 提出了伟大中国“三部曲”，请分别说出事哪三部曲？
