请教英语选择题[初一](在线等)

1.Jim is trying his best to learn Chinese.___C____
a.So does Mike b.So Mike does c.So is Mike d.So Mike is
jim正努力学英语,Mike也是这样,如果表示一个人这样,另一个也这样,用完全倒装,即 so+助动词\系动词+主语,类似的适用于neither,表否定.如果表示这个人确实这样,用部分倒装,即 so(neither)+主语+助动词\系动词 如本题可说 so jim is
2.Both Tim and Tom take part in __A____
a.the 400-metre race b.the 800metre race c.the 800-metres race d.the 800-metres race
400-meter 做形容词,meter后不加S
3.The river is so wide for a child __C____
a.to swim b.to swim on c.to swim across d.swimming
这条河对孩子们游过去来说太难了
4.When I got to the check-out,I realized I _C____ my purse at home
a.left b.have left c.had left d.had forgotten
把什么忘在什么地方,用Left,不用forget
另外,“忘”发生在 “意识到之前”所以用过去完成.
我来解释下吧,不一定对,一楼回答的很好
如果还有什么问题,随时问,