每日背誦:A certain amount of care or pain

A certain amount of care or pain or trouble is necessary
    for every man at all times.
    A ship without a ballast is unstable
    and will not go straight.
    一定的憂愁、痛苦或煩惱，對(duì)每個(gè)人都是時(shí)時(shí)必需的。
    一艘船如果沒(méi)有壓艙物，便不會(huì)穩(wěn)定，
    不能朝著目的地一直前進(jìn)。