if you should see James,ask him to phone me.这里为什么填should?为什么

if you should see James,ask him to phone me.这里为什么填should?为什么 If he ( )help me,I should be very grateful to you.为什么只能填shou ___it with me should be a good choice .Trust me.这里为什么不能填If y Please ask him to see me.为什么要加to? Ask him to call his office as soon as possible if you should If you should see him,please ___him my regards. Ask him to ring me up if you ____________ him. if you want to see ( )(远）,you should stand higher应该填farther还 If you are ill,you should see a doctor.为什么等于When you are ill If by any chance Peter should phone,can you tell him I'll ta If ___ calls me when I am out,ask him to leave his phone num Peter（ ）phone.if he does,could you ask him to ring later?(ca