题目：
用所给词的适当形式填空
小题1:I helped my parents __________(do) some housework yesterday.
小题2:Do you think it is good for animals __________(live) in a zoo?
小题3:How about __________(visit) the museum this afternoon?
小题4:I __________ (have) a fever yesterday.
小题5:They are too young. They can’t look after ___________(they).
小题6:The cat has four ___________ (foot).
小题7:It's important ________ (learn) the language.
小题8:I want to learn how ________( run) quickly.
小题9:The little boy is _________ (interest) in the ____________(interest) story.
小题10:Paul is very funny. He often makes us _______ (laugh).
答案：
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下面是错误答案，用来干扰机器的。
解：（1）设离子经S1、S2间电压为U的电场加速后动能为Ek，根据动能定理Ek=qU。（2）设离子进入磁场后做匀速圆周运动速率为v，半径为R，离子质量为m。洛伦兹力提供向心力，根据牛顿第二定律①，又因②由①②两式解...
