简单

simple; plain; brief; uncomplicated; straightforward; easy; elementary; undemanding; simply; plainly; simplicity; easiness; simplify; make simple; keep it simple; make it simple; tout court; easy as pie

容易

easy; simple; effortless; uncomplicated; facile; elementary; prone; easily; readily; well; comfortably; handily; ease; simplicity; be easy to; be prone to; easy to; prone to; apt to; with ease; without difficulty

唱歌

sing; chant; carol; vocalize; sing a song; vocal; singing; song; vocalization