嚴(yán)格說(shuō)來(lái),這是一個(gè)由兩個(gè)祈使句構(gòu)成的并列句.
1.第一分句：Look carefully.
主語(yǔ)you省略,謂語(yǔ)look,狀語(yǔ)carefully
此句是 S + V 結(jié)構(gòu),即：主語(yǔ) + 謂語(yǔ).
2.第二分句：tell me what she looks like
該祈使句是一個(gè)主從復(fù)合句,含有一個(gè)what引導(dǎo)的賓語(yǔ)從句.
主句是tell me...
賓語(yǔ)從句是what she looks like
引導(dǎo)詞what做介詞like的賓語(yǔ),這個(gè)介賓短語(yǔ)在句中做表語(yǔ),主語(yǔ)是she,系動(dòng)詞looks.