,英语好的一起进 1.He went to supermarket alone ,(同义句)He went to supermaket _____ _____.2.( )There_____ great changes in our hometown in the past twenty years.A.are B.were C.has been D.have been 3.已知甲乙两人同时从同一地点出发,甲的速度为7,乙的速度为3,乙一直向东走,甲先向南走10步后又斜向北偏东方向走了一段后与乙相遇,那么相遇时,甲乙各走了多远?（用一元二次方程解+勾股定理,）,
,英语好的一起进
1.He went to supermarket alone ,(同义句)
He went to supermaket _____ _____.
2.( )There_____ great changes in our hometown in the past twenty years.
A.are B.were C.has been D.have been
3.已知甲乙两人同时从同一地点出发,甲的速度为7,乙的速度为3,乙一直向东走,甲先向南走10步后又斜向北偏东方向走了一段后与乙相遇,那么相遇时,甲乙各走了多远?（用一元二次方程解+勾股定理,）,
by himself.
C.has been ， 有in the past twenty years 提示，要用现在完成时。our hometown 是单数，用has
设甲斜向北走了x步，乙向东走了y步，
所以10^2+y^2=x^2,(10+x)/7=y/3
计算出结果就对了。
1.by himself
2.B
3.设乙走了x步
x/3=10/7+开根(100+x平方)/7
解出x=10.5
即乙走10.5步，甲走10+14.5=24.5步
1, by himself
2, D
2选D
1.by himself.原句是“我独自去了超市”同义句为“我一个人去了超市”.
2.选D.in the past twenty years是“在过去的二十年中”,因此要选现在完成时,changes为复数,排除C.
3.方法一：设乙走了x步
x/3=10/7+开根(100+x平方)/7
解出x=10.5
即乙走10.5步,甲走10+14.5=24.5步
方法二：设时间为t,100+(3t)平方=《7（t-10/7）》平方,解得t=3.5.所以甲走了14.5+10=24.5.乙走了10.5.