—Can you go for a picnic with us tomorrow? —I’m sorry I can’t. I do my homework.A. have to

问题补充：

—Can you go for a picnic with us tomorrow?

—I’m sorry I can’t. I do my homework.

A. have to B. has to C. has

答案：

解析：句意：——明天那你能和我们一起去野餐吗？——对不起，我不能。我必须做作业。主语是I，谓语用非第三人称单数形式，故用have to必须，不得不。故选A。