There are several possibilities, but most simply you may say: 'ningen ga yowai.'
'Watashi WA yowai desu.'
ningen
You may say 'Doushite boku WA konna ni yowai,' among others.
You would call them a "person" or better yet, call them by their name.
NO "we" cant ... there are people that don't believe in a god ...
we cannot as yet say for certain but it is unlikely as there is no oxygen or water
I would say "weak at" eg I am very weak at mathematics,
Necessities are such needs of human beings that are without them human beings cannot be survived like Food, Shelter, Clothing and Family; we can also say them basic needs whereas luxuries are such needs by which human beings can live but these are wanted to make life easy and luxurious like Car, Motorbike, Mobile etc By: Musadiq
"Omae WA yowai. Naze yowai ka? Tarinai kara...nikushimi ga." (You are weak. Why are you weak? Because you lack... hatred." Here it is on youtube with Japanese subtitles http://www.youtube.com/watch?v=LzyP-VfoqFA&feature=related
Human beings (some also say Dolphins, but it is far from proven) are the only creatures on earth that have language.
We have body hair and can survive for long durations away from water. Safe to say we're mammals.
Yes,we can say that all living beings are mutants.