使用吊环应注意什么问题？
参考答案：
使用吊环应注意：
（1）使用前应检查螺杆是否有弯曲变形，丝扣规格是否符合要求，丝牙有无损伤等。
（2）吊环拧入螺孔时，一定要拧到螺杆根部，不宜将吊环螺杆部露在外面，以免螺丝受力后，产生弯曲而断裂。
（3）两个以上的吊点使用吊环时，两根钢丝绳角不宜大于60°，以防吊环受力过大而造成弯曲变形，甚至断裂。如遇特殊情况，可以在两吊绳之间加横吊梁以减小吊环受到的水平力。
（4）吊环的允许吊重可根据吊环丝杆直径查表。
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| It's Sunday. We are in the park now. __1__ is a big and beautiful park. __2__ many people in it. We all like this park. The park__3__ a lake. too.We can boat on the 1ake. But we__4__ swim in it. It is dangerous. Look at that family. They are__5__ the tree. The boy is on the left of his father. The family bring their__6__ to the park. It is a cat,a white cat. How lovely! The boy has a __7__ in his hand. He wants to fly it. But I think they__8__ look for the right place. It's not a good place here. There are too many trees. The mother has a beautiful handbag. It's __9__ . I like the colour. It's the color of the sky (天空). There is a __10__ on the tree. It says" Don't climb (爬) the tree!" But the cat is in the tree now. | |||
| ( ) 1. A. He ( ) 2. A. There are ( ) 3. A. have ( ) 4. A. can ( ) 5. A. on ( ) 6. A. son ( ) 7. A. ball ( ) 8. A. are ( ) 9. A. yellow ( ) 10. A. sign | B. It B. There is B. haves B. can't B. in B. pet B. plane B. must B. black B. newspaper | C. They C. There have C. is C. must C. under C. teacher C. shirt C. do C. white C. book | D. There D. There has D. has D. must't D. into D. cat D. kite D. can D. blue D. bag |