被动语态初步（be+过去分词） — 英语填空题
题目
用括号内动词的适当形式（被动语态）填空。The new science lab ___ ___ (build) last year, and now all the machines in it ___ ___ (test) once a month. Every year, a science fair ___ ___ (hold) in this lab, and students' best works ___ ___ (show) to the whole school. 一空一词。