I teach ESL through content areas (history and science) with a New York State regents exam at the end of the year. I have found that they best way to scaffold (quickly) is to have pictures on my SMARTboard files. If, for example, I have a question about the digestive system of a grasshopper, I better make sure that I put up a picture of a grasshopper on the SMARTboard before I have the kids read the question. This allows them to make a connection with the vocabulary but it doesn't waste any of our precious classroom minutes.