
圬工梁拱劣化:混凝土裂缝达到下面()可评定为A1级劣化。
A.钢筋混凝土梁裂缝宽度0.3-0.5mm
B.预应力梁纵向裂缝宽度0.2-0.3mm或封端混凝土开裂
C.混凝土拱圈横、斜向裂缝宽度达0.3mm,纵向裂缝宽度>0.5mm
D.框构裂缝宽度>0.5mm


A.钢筋混凝土梁裂缝宽度0.3-0.5mm
B.预应力梁纵向裂缝宽度0.2-0.3mm或封端混凝土开裂
C.混凝土拱圈横、斜向裂缝宽度达0.3mm,纵向裂缝宽度>0.5mm
D.框构裂缝宽度>0.5mm
When a rare disease ALD threatened to kill the four-year-old boy Lorenzo, his parents refused to give up hope. Doctors explained that there was no cure for ALD, and that he would probably die within three years. But Lorenzo’s parents set out to prove the doctors wrong.
The parents devoted themselves to keeping their son alive and searching for a cure. But doctors and the families of other ALD patients often refused to take them seriously. They thought the efforts to find a cure were a waste of time, and drug companies weren't interested in supporting research into such a rare disease.
However, the parents still refused to give up and spent every available hour in medical libraries and talking to anyone who would help. Through trial and error(反复实验), they finally created a cure from ingredients(调料) commonly found in the kitchen. The cure, named “Lorenzo’s Oil”, saved the boy’s life. Despite the good results, scientists and doctors remained unconvinced. They said there was no real evidence that the oil worked and that the treatment was just a theory. As a result, some families with ALD children were reluctant to try it.
Finally, the boy’s father organized an international study to test the oil. After ten years of trials, the answer is: the oil keeps ALD children healthy.