----_______ are stamps used _______? ----Sending letters.
| A．Why, for | B．What, for | C．What, / | D．How, for |
It may take _________ years to make such robots ．
| A．hundred of | B．two hundreds |
| C．hundreds of | D．hundred |
There will be less ________．
| A．trees | B．people |
| C．pollution | D．cars |
I will be an engineer ____ ten years．
| A．after | B．in | C．at | D．on |
Last year I went to Beijing and ________ it.
| A．fell in love with | B．fell love with |
| C．fall love in | D．fell in love to |
There _______ a robot in every home．
| A．will have | B．will be |
| C．are | D．are going to be |