Grab Guinness Records

Underwater fishing is dangerous, so it is very necessary to make preparations in advance. Before underwater fishing, please use lifting tools to prepare in advance. Next, follow Xiaobian to understand

Underwater cutting is another underwater project. With the rapid development of economy, underwater cutting is more and more widely used. What are the environmental requirements of underwater cutting?

1. Underwater search: two search team members in each group enter the water in the order planned in advance. The team member who arrives at the bottom table first must wait until another team member a