It began in 1919,what President Hoover called the "noble experiment".这里为什么用what而不用which

It began in 1919,what President Hoover called the noble experiment.这里为什么用what而不用which It was in 1990 ------he began to work.It was 1990 ------he began to work.用when/that填空 It is cold and white.It falls from the sky.The more you dey it in the sun,the wetter is becomes.Wha the trouble began in Nanjing,as reported in the China D_____ on December it. while they were talking it began to rain and Dimitri stayed in Aleko's house until the rain这句话中while they were talking it began to Today,when I sat in a park,it suddenly began to rain.有关的短文 He said nothing about it,and began to talk about putting in commas. he said nothing about it,and began to talk about putting in commas.改为同义句 Papermaking began in China and it then__________ (spread )to North Africa and Europe he said nothing about it,and began to talk about putting in commas 是什么意思 It was not until her mothercame in (that) the girl began to prepare her lessons.翻译 No sooner had they got in the wheat than it began to rain heavily. It was a great e______ when the war began in 1936空中填什么 Professor Luo began to work in this lab five hours ago的同义句改为：It _____ ______ five hours _____Professor Luo began to work in this lab It ()five years()i began to study Englishis,began为什么 By 1990,production in the area is expected to double ________ of 1980.A) that B) it C) one D) wha这几个词 有什么区别啊 that 和 it 有什么区别？ 英语翻译a war between two states can end much where it began withour the adversaries feeling in mortal danger句子错了，a war between two states can end much where it began without the adversaries feeling in mortal danger paper making began in China and from here it ____to europe and north americaa,spreadb,grewc,carriedd,developed