7.Although the causes of cancer ____， we do not yet have any practical way to prevent it.
| A．are being uncovered | B．have been uncovering |
| C．are uncovering | D．have uncovered |
She _____ as the illness grew worse.
| A．strengthened | B．deepened | C．weakened | D．thickened |
They'll be here soon. _____ ,let's have some coffee.
| A．However | B．Meanwhile | C．Unfortunately | D．Especially |
People _____ have been invited here to discuss what to do next.
| A．refused | B．affected |
| C．influenced | D．concerned |
My friends admitted what they did but I lied, _____ the truth.
| A．confirming | B．refusing | C．approving | D．denying |
Do you think the bikes will be _____ by the electronic bicycles?
| A．placed | B．replaced | C．changed | D．covered |