29．______ your own needs is as important as learning to express your emotions.
A
Understand
B
Understanding
C
Understood
D
Having understood
Understand your own needs在句子中作主语，动词作主语要用动名词或不定式。所以选B。
考查非谓语动词作主语。
没有弄清动词在句子中所作的成分而误选其他选项。