When he was in his fifties Marx began to learn English.我想问的是 为什么 WHEN HE 后面跟的是WAS 而不是IS?这个叫什么从句?是不是后面从句用什么时态,前面主句就要用同样的时态?

when he was in beijing-----his-----in england同义填空 in his fifties=when he was ____ _____fifty When he opened his door,he found everything in the room was g___ When he returned to his country,he found it was war.(at on in with) He needed to contact his friends and family when he was in Pinhurst. He m_____ his parentes very much when he was in Beijing. 英语单词连词成句forties/ English/ to/ was/ began/ he/ his/ when/ he/ in/ learn He often ______(thinks of) his parents when he was study in Canada.填一个词. He often ______________ (依靠) his sister when he was in Shanghai. when he was in his college days,he used to_____ long hair.dress wear remain grow 英语翻译翻译：He lost his wallet yesterday when he was in acrowded bus . He showed his （）（able）in drawing when he was quite young 词形变化. He was efficient in his when he was加 in his thirsties还是in the thirties his mother died when he was five and not long after his father was killed in a battle怎么翻译 He became a teacher when he was __.A on his twenties B in his twentiesC in his twenty D at his twenties选哪个, He served in the army in the 1940's,when he was in his twenties.怎么翻译, His father died the year when he was born.与His father died in the year when he was born.哪一句对