1.This is the first time astronomers__the whole process of a black hole__a star,from its first to nearly final bites.a)see,eat b)have seen,eating c)saw,eaten d)had seen,eat2.A team of Japanese scientists have found a gene closely__to nicotine addicti

this is ____lesson 1.we first 2.us first 3.the our first 4.our first This is not the first Around this world ,the last is first. This is my first bag中first前要加the吗 this is the first lesson=this is________. this is the first time this was the first time 怎么用,有什么区别? This has been the first time与this is the first time有什么区别 This is the first man ___(walk)to the moon . lesson the is first this week of the . This is the first two sections of the book. This is the first lesson ( )the new term day,term,of,this,the,the,is,first,new This is My first This is the first time that I ______(be)there NO,This is the first time I chat with you This is the first time that I_the Summer Palace.(visit) the day this it is first term of造句 This is a b------- book than the first one.