____all the required papers. he didn't answer the questions fluently in class.
| A．Having not read | B．Not having read | C．Not read | D．Not to read |
I cannot hear the professor clearly as there is too much noise ________ I am sitting.
| A．before | B．until | C．unless | D．where |
Sophia got an e-mail ________ her credit card account number.
| A．asking for | B．ask for | C．asked for | D．having asked for |
Young people may risk ________ deaf if they are exposed to very loud music every day.
| A．to go | B．to have gone | C．going | D．having gone |
I have no idea ________ the cell phone isn’t working, so could you fix it for me?
| A．what | B．why | C．if | D．which |
The students are looking forward to having an opportunity ________ society for real-life experience.
| A．explore | B．to explore | C．exploring | D．explored |