[简答题]硬横梁（角钢）不得变形和开焊，锈蚀面积不得超过20%，焊接处不得锈蚀。

It seems you always forget--your reading glasses when you are rushing to work, your coat when you are going to the cleaners, your credit card when you are shopping...
Such absent-mindedness may be{{U}} (47) {{/U}}to you; now British and German scientists are developing memory glasses that record everything the{{U}} (48) {{/U}}sees.
The glasses can play back memories later to help the wearer remember things they have forgotten such as where they left their keys. And the glasses also{{U}} (49) {{/U}}the user to "label" items so that information can be used later on. The wearer could walk around an office or a factory identifying certain{{U}} (50) {{/U}}by pointing at them. Objects indicated are then given a{{U}} (51) {{/U}}label on a screen inside the glasses that the user then fills in.
It could be used in{{U}} (52) {{/U}}plants by mechanics looking to identify machine parts or by electricians wiring a{{U}} (53) {{/