| 1. | Would you mind cleaning the blackboard ? ( no , i ' ll do it 你能帮忙擦擦黑板吗? (可以。 ) |
| 2. | Who is supposed to clean the blackboard today 今天应该由谁来擦黑板 |
| 3. | The teacher suggested that we ( should ) clean the blackboard after class 老师建议我们课后把黑板擦了。 |
| 4. | He must be in the classroom , i saw him clean the blackboard just now 他一定在教室里,刚才我看到他在擦黑板。 |
| 5. | The head teacher demanded that we ( should ) clean the blackboard before every class 班主任要求我们每节课前要擦干净黑板。 |
| 6. | The students are cleaning the classroom . some are cleaning the blackboard ; some are sweeping the floor ; the other students are cleaning the window 学生们在打扫教室。一些在擦黑板,一些在擦地板,另外的都在擦窗户。 |