试题题干
Complete each of the following sentences with the proper form of the word in brackets.
(loud) The students began to enter the classroom and Anna was startled at their
.
参考答案
试题解析
此处缺少名词。
their是形容词性物主代词，所以其后接名词。变loud为名词loudness。
句意：学生们开始走进教室，Anna被他们的吵闹声吓了一跳。