The adverb "怪不得" is used to indicate that one has realized the cause of a certain situation and therefore is no longer confused. It is often used as an adverbial in front of the subject-predicate construction, preceded or followed by snetences or phrases that indicate the cause, for example:
guài bù de
no wonder//so that's why
Guàibùde tā bùzàigōngsī, tā qù dùjià le.
No wonder he was not at the
company, he was on a vacation.
Guàibùde nǐ zhème yǒujīngyàn.
No wonder you are so experienced.
have the experience in//
Tā měitiān jiànshēn, guàibùde shēncái
He works out everyday,
no wonder he has such a great figure.
v. do fitness
身材 shēncái n. stature
Tāmendeshílì zhēnde hěnqiáng, guàibùde
They're really unbeatable,
no wonder they're the champions.
Nǐshuōdeduì, guàibùde dìngdān zhèmeduō.
You're right, so that's why
there are so many orders.
Zhèlǐ tàiměile, guàibùde hěnduōrén lái lùyíng.
It's a beautiful place, so that's why
many people come here to camp.