用吊件将吊杆与主龙骨连接固定，并使主龙骨保持水平；

Use the hook fitting to link and fix the boom and key keel, keep the key keel horizontal;

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用吊件将吊杆与主龙骨连接固定，并使主龙骨保持水平；

Use the hook fitting to link and fix the boom and key keel, keep the key keel horizontal;

youdao