It’s very dangerous to _______ these viruses without any protection.
| A．be exposed to | B．expose to | C．expose | D．be exposing to |
________ entered the classroom _________ the bell rang.
| A．We hardly had, before | B．Hardly had we, when |
| C．Hardly had we, than | D．Hardly did we, when |
So loudly ______ that every one of the class could hear him.
| A．did he speak | B．did he spoke |
| C．spoke he | D．he spoke |
---What do you think made her so upset?
---_____________ her hometown.
| A．As she missed | B．Missed | C．Because of missing | D．Missing |
Though ___________ to see us, the professor gave us a warm welcome.
| A．surprising | B．was surprised | C．surprised | D．being surprised |
The teacher stressed again that the students should not ________ any important details while retelling the story.
| A．bring out | B．let out | C．leave out | D．make out |