重點講解：
1. be surrounded by
圍繞；環繞；
eg. It's also called oriental venice and surrounded by water.
古鎮被綠水圍繞，因此也享有東方威尼斯的美譽。
eg. The sheep were surrounded by stockade.
羊被柵欄圈著。
2. keep out
不許入內； 阻止；
eg. She stamped her feet on the pavement to keep out the cold.
她在人行道上跺著雙腳取暖。
eg. They sandbagged their homes to keep out floods.
他們在房屋周圍堆沙袋以抵御洪水的侵襲。
3. keep sb. from sth.
阻止（或防止、阻礙）…做；
eg. He slides the bolt in place to keep the door from swinging.
他推上插銷，使門不搖晃。
eg. I tucked some plastic wrap around the sandwiches to keep them from getting stale.
我用塑料包裝紙把三明治裹起來，防止變質。