问：What's she doing? 答：She is ( ) some shopping in the shop.

doing,
is doing表示现在进行时,他正在做购物这件事.
shopping在这里是名词形式,因此不用担心动词的重复.is doing some shopping连起来表示在购物.

doing
问 她在做什么
答 她在商店里买东西

do some shoping 买东西

going

doing

be doing 现在进行时

do shopping 词组购物

doing,现在进行时所以加ing

going shopping 是去购物 doing shopping 是正在购物。