The past tense of cost is usually “cost”.
Very rarely is the past tense “costed” used, it’s more common to just say cost.
When Students take work home they are doing more that helps them learn. Most of the time people who don't do homework have lower grades.
Answer:
He promises to teach him to write whole sentences and to add numbers. Anil knew all about the theft. He knew how and when Had Singh stole the money and put it back under the mattress.
What it means is that he wouldn't have been able to get where he got if it hadn't been for the scientific achievements of his predecessors. If it hadn't been for these "giants" that enabled him to see so far, he wouldn't have been able to make all the discoveries that he did. For those coming after him, he was a giant that enabled them, and so laws and theories and scientific knowledge always increases based on the knowledge before it.
