高中英语语法题,请大侠帮个忙,

题目

高中英语语法题,请大侠帮个忙,
① ___is worth mentioning that university lessons can't be the only prepartion for all of the situations __in the working world.
what that
我不明白为什么第二个空填that
②Scientists believe native Americans arrived by crossing the land bridge that connected Siberia and ____ more than 10,000 years ago
A.this is Alaska B.Alaska is now C.is now Alaska D.what is now Alaska
为什么选D
③_____,he doesn't know how to manage people well.
A.Smart as Jack is B.as Jack is smart
请问是选哪个?
③为什么选A，D没打错哦

答案

①第二个填that是因为它是定语从句,preparing是先行词,先行词在句子中做主语,所以填which或者that,但是先行词前面有the only或者the very 时就只能填that了②这里选D.用what代替native Americans arrived by crossin...