?像水一样不稳定

... above water：脱离困境的 as unstable as water：像水一样不稳定，变化无常 as weak as water：身体非常虚弱；意志薄弱；性格懦弱 ...

?象水一样不稳定

as unstable as water 象水一样不稳定, 变化无常..

?反复无常

... as ugly as a scarecrow丑极了 as unstable as water反复无常 as warm as toast暖烘烘的，热得满面红光的 ...