阅读下面短文，请从短文后所给各题的4个选项(A、B、C、D)中选出一个最佳选项。

     All ESL(English as a Second Language) writing teachers can find a valuable resource in pictures: drawings, photographs, slides, cartoons, magazine advertisements, graphs, tables, charts and maps. First of all, pictures provide a shared experience for students in class, a common base that leads to a variety of language activities. When students write about a personal topic like "My most frightening experience," the material is not shared. Except for predicting the use of the past tense, there is little that the teacher can do to prepare a whole class to deal with the vocabulary and sentence patterns that the writers will need. With a picture, however, all students, after close observation of the material, will immediately need the appropriate vocabulary, idioms and sentence structures to discuss what they see. Pictures are also valuable in that they provide for the use of a common vocabulary and common language forms. In addition, a picture can be the basis for not just one task but many, ranging from fairly mechanical controlled compositions, sentence-combining exercises, or sequencing of sentences to the writing of original dialogues, letters, reports or essays. Thus, a whole series of connected activities can be generated from the source of one picture. Finally, because everybody likes to look at pictures, their use in the classroom provides a stimulating focus for students' attention. Pictures bring the outside world into the classroom in a vividly concrete way. In short, a picture is a valuable resource as it provides a shared experience, a need for common language forms to use, a variety of tasks and a focus of interest for students.