1

那時

nàshí

then at that time in those days

=2

你

nǐ

you (informal, as opposed to courteous 您 nín)

=2

你

nǐ

you (Note: In Taiwan, 妳 is used to address females, but in mainland China, it is not commonly used. Instead, 你 is used to address both males and females.)

3

在學

zàixué

to be at school; to be studying

=4

校

jiào

to check; to collate; to proofread

=4

校

xiào

(bound form) school; college (bound form) (military) field officer

=5

嗎

má

(coll.) what?

=5

嗎

mǎ

used in 吗啡 mǎfēi

=5

嗎

ma

(question particle for "yes-no" questions)