（）在生产过程中，焊工对焊工工艺文件可根据实际情况灵活执行。
参考答案：错
-What do you want to do next? We have half an hour until the basketball game.
-________. Whatever you want to do is fine with me.
A．It just depends.
B．It is up to you.
C．All right.
D．Glad to hear that.
仔细观察下图：
（1）上图是什么工具？
______________________
（2）它是什么时期由谁发明的？
（3）它比欧洲早多少年？
