潜水时要小心一头扎进水里。

Be careful when diving(跳水)into the water headfirst.

罗宾不加思索地从小屋里冲了出来, 爬上栏杆, 一头扎进水里.

Without pausing for thought, Robin dashed from the cabin, clambered onto the handrail, and plunged in.

这意味着我们在房子外面能有一次喷射水枪大战或者我们可以去海边，一头扎进水里。

This means that we could have a water fight with squirt guns outside the house or we could go to the ocean and splash in the water there.