World war I ___in 1937.
| A．has broken | B．was broken | C．broke out | D．was breaking out |
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 |
— ____ 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 |
— Would you please go to the cinema with me ?
— Yes , I ____ .
| A．will | B．would | C．could | D．should |
I''m surprised that he ____ to help me when I needed his help .
| A．should refuse | B．would have refused |
| C．should have refused | D．may have refused |