It is these poisonous products _____ can cause the symptoms of the flu, such as headaches and aching muscles.
| A．who | B．that | C．how | D．what |
. ___________ the classroom, the students went to the playground to watch the football match
| A．To clean | B．Having cleaned | C．Cleaned | D．Cleaning |
1. I’ve heard him ______ about you often.
2.
| A．speak | B．speaks | C．spoke | D．Speaking |
. I went to see him, _______ him out.
| A．finding | B．find | C．only to find | D．to finding |
. He didn’t know _______ or stay.
| A．to leave | B．if that he should leave | C．if to leave | D．whether to leave |
.---Will the Smiths go abroad this summer? ---No, they finally decided _______ .
| A．to | B．not going | C．not to | D．not to be going |