However, at times this balance in nature is disturbed by human activities, _______ a number of possibly unforeseen effects.
| A．lying in | B．calling in | C．taking in | D．resulting in |
If you ____ do as I tell you , you ____ go to the party .
| A．can ; shan''t | B．wil l; won''t | C．won''t ; shall | D．won''t ; shan''t |
Li Ling was a diligent boy . He ____ go to school though it was raining hard .
| A．was able to | B．could | C．couldn''t | D．wasn''t able to |
The work ____ be finished in such a short time .
| A．wasn''t able to | B．couldn''t | C．ought | D．could |
— ____ he open the door ? — Yes , please .
| A．Will | B．Shall | C．Does | D．Would |
— Do you have to take care of your mother at home ? — Yes , I ____ .
| A．do | B．have to | C．have | D．shall |