Do you think he have a basketball?为什么是have ,而不是has

Do you think he have a basketball?为什么是have ,而不是has do you think if he ___ (have) a good eating habit? l think he needs help（便否定） Do you have a headache 否定回答 Do you think Davied have one?I think ( ). What do you think he is doing还是Whai do you think is he doing? what do you think he bought还是what do you think did he buy who is he 和do you think 合成一个句子who do you think he is 》 strange that he _ without saying good-bye to us.A should have gone out B should go out另外What do you think is good?Do you think what is good?do you think 可以放句首吗? ---Do you think he is lazy?---I____so once ,but I don't now.A mey have thought B can have thoughtCmay thinkDmight think答案为什么选A? W here do you think ___ he ___ the computer?-Sorry,I have no idea．选什么, Do you think if he ___(have) a good enting habit?my father‘s eating habits（ habit Do you think ( )he should go to the music club or not sorry ,I have no idea.宾语从句? How do you think you have fared today 急 DO you think you will have your own robot Do you think these have any special meaning to you? do you think what you should have as a pilot? do you think what he said is right =do you think ____ ____ ____ridht. do you think what happenedto her,do you think what he happened,这两句哪句是对的,为什么?