Early submersibles were dangerous and could remain underwater for only a few hours at a time. How did Robert Ballard solve this problem

He designed a remote-controlled submersible.

Explanation:

in "letter from a birmingham jail," king argues that there are four basic steps in any nonviolent campaign: "[c]ollection of the facts to determine whether injustices exist; negotiation; self purification; and direct action." finally, direct action is taken and acts such as boycotts and sit-ins are staged.

life is