—I don’t understand why you didn’t go to the lecture yesterday afternoon.
—I’m so sorry.But I________my homework.
| A．had done | B．was doing |
| C．would do | D．am doing |
New ideas sometimes have to wait for years before _____ .
| A．fully accepted | B．having fully accepted |
| C．fully accepting | D．being fully accepted |
To succeed in a scientific experiment _____ .
| A．carefulness is need | B．carefulness is one needs |
| C．one needs to be careful | D．one need being careful |
The long lasting war, ______ with blood and deaths, ended in people’s sadness, _______ no result．
| A．filling；reached | B．filled；to reach |
| C．filling；would reach | D．filled；reaching |
On December 28, 2009, a terrible tsunami happened in the coasts of South and Southeast Asia, _______ over 25,0000 people.
| A．killing | B．had killed | C．killed | D．having killed |
I’ll do whatever I can _________ my English.
| A．improve | B．to improve | C．improving | D．to improving |