I had difficulty _______ the maths problem.
A：working out
B：work out
C：to work out
D：works out
假如现在鸡棚有62只鸡，现在养殖场卖出28只鸡，然后买回21只鸡仔，那么养殖场里现有____只鸡。
按拼音写汉字
nuǎn huo
yè yīng
è bà
____
