classifier for birds and certain animals, one of a pair, some utensils, vessels etc[cedict]
手
shǒuㄕㄡˇ
hand; (formal) to hold; person engaged in certain types of work; person skilled in certain types of work; personal(ly); convenient[cedict]
可以
kě yǐㄎㄜˇ ㄧˇ
can; may; possible; able to[cedict]
掌握
zhǎng wòㄓㄤˇ ㄨㄛˋ
to grasp (often fig.); to master; to know well; to understand sth well and know how to use it; fluency; to control; to seize (initiative, opportunity, destiny)[cedict]
四
sìㄙˋ
four; 4[cedict]
个
gèㄍㄜˋ
individual; this; that; size; classifier for people or objects in general[cedict]