Rewrite the following sentences by adding words from the parentheses. replace the modal verb can (could) with the expression to be able to if necessary. 1. i can give you my book for a couple of days (after i have read it). 2. he can ski (for ten years). 3. we knew that she could swim (since a child). 4. you cannot take part in this serious sport competition (until you have mastered good skills).