题目内容
These machines ought________ once a week.A. to be cleaned B. to cleaned C. clean D. be cleaned
答案:A
提示:
提示:
| ought
to do应该做某事,这里是被动语态,机器被清洗。
|
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题目内容
These machines ought________ once a week.A. to be cleaned B. to cleaned C. clean D. be cleaned
| ought
to do应该做某事,这里是被动语态,机器被清洗。
|