单项选择题

Galvin Toys
44 Broadhurst Lane
Compton
Los Angeles
To the manager,
I recently purchased a Mad Boyz Trampoline from your store as a present for my 7-yearold son. I assembled the equipment (28) , making sure to follow the instructions. Initially, it worked well, and my son enjoyed playing on it.
However, after only 3 days of use, the material on the trampoline ripped, leaving it unusable. Naturally, my son was very disappointed because of this. But the real problem is that he could have been badly hurt had my husband not (29) the problem so quickly. This is a serious issue that I hope you can address. I was very surprised to discover that, in the event of a tear, there are no additional (30) features that offer children protection. Accordingly, I recommend that you withdraw this product and replace it with a more appropriate and secure model.
sincerely,
Riva Choudry

A.spotted
B.marked
C.assigned
D.knotted