Tom cleans his bedroom once a week ,not very
网友回答
填often,在频率副词中只有often 可以被程度副词修饰
======以下答案可供参考======
供参考答案1:
应该是often。
usually和often虽然都是经常的意思，但是usually指的事情发生频率远远高于often。
而且，usually的用法常用于I usually do sth.
供参考答案2:
often .very 一般加often。usually一般跟在主语后面
供参考答案3:
often