do you think if i should take part in sport?为什么错了?是为什么应该用that而不能用if！

(if you work hard i think you can do better) Do you think I Yes But if you know you will do it.I think you can do well If you do think I tell a lie to you ,I have nothing toexplain什么意思? If you really want my advice i do not think you should quit school If I can read,do you think I will come here to buy glasses 如何翻译 I think you do it what do you think i Think that I criticize me to you when missing you ,answer if you will be:Do I also miss you . If you get these things on your birthday,what do you think of theses gifts?1.I think flowers are ________because_______________2.I think computer is ________because______________ if you these things on your bithday ,what do you think of these gifts 1.i think flowers are ______ because ________________________________ .2.i think ______________________________________________________. if you do you'll be A:I think I'm going to stay at home.B:If you do you'll be sorry .请问这里的If you do you'll be sorry if one day you left me .what should i do?i hope you can understand my think中文 If you love do not let me out of La Tortura.I think I really love the wrong people you. If you can,I think loses memory I think you can do it ( )(you) -Do you know if Jim____ to piay football with us - I think he will come if he ____ free tomorrow. Do you think what should I do 还是Do you think what I should do