It was on July 1,1988 that I joined the army为什么要用that,而不用when/which

When was the PRC founded?It was founded on ( ) A:July 1,1921 B:October1,1949 C:August 1,1927. It was on July 1,1988 that I joined the army为什么要用that,而不用when/which -When was our party founded?-it was founded_ A.on October 1,1948 B.in May 1922 C.-When was our party founded?-it was founded_A.on October 1,1948 B.in May 1922 C.on july 1,1912 英文“It was July 1st”中文意思 when was our party founded.It was founded-When was our party founded?-it was founded_A.on October 1,1949 B.in May 1922 C.on july 1,1921 D.in August,1927 It was July 1,1997 ___ saw the return of Hong Kong to the motherland.A.that B.when C.which D.in which为什么不是B .July 1,1997 这个能做主语?前面不用加 on吗 It was July last month中文意思 he was born in Shanghai on July 1st,1998.(对in Shanghai on July 1st提问)____ ____ ____ was he born? -When was the PLA founded?-It was founded on ＿＿.A.July 1,1921B.October 1,1949C.May 1,1922D.August 1,1927PS:我是不知道PLA是什么,汗.,现在的选择题好离谱,... it is on July 1,1997 that our gonvernment ____ ____ Hong Kong. i was born on july eighth的同义句 when were you born?i was born on July 3还是July 3rd?RT Sam was ( )denmmark ( ) July.a.in,on b.on,in c.in,ind.on,on My birthday is .It is on July 19th 填空 it was on _____Saturday in______ July of 2009 that the famous scholar of Chinese.A / / B/ the C a the Da a The book is set in the American South in the nineteen thirties.But it was published fifty years ago,on July eleventh,nineteen sixty.这句话怎么翻译! when is your birthday?A ：It is in july the thirtieth B:It is on july thirtieth C:It falls on july D:It falls on july the thirtieth It was july 7th 2006划线部分提问划july 7th 2006 —was the—?