It’s necessary for us English well.
| A．learn | B．to learn | C．learned | D．learning |
—Let’s go dancing tonight.!
—Sorry, I ________.I have to go to my guitar lesson.
A. mustn’t B. needn’tC. can’t
Listen! Someone _________ for help!
A. called B. is calling C. has called
I am going to make ________special house for my pet pig this weekend.
A. an B. a C. the
Healthy food and exercise help ________to study better.
A. us B. we C. our
________is dangerous for us to swim in the river alone.
A. It B. That C. This