Jim, you can me, but can't me in class.
A:help; chat
B:help with; chat with
C:help; chat with
D:help with; chat
“酒是陈的香”,其原因之一是酒在储存过程中生成了具有香味的乙酸乙酯,在实验室我们也可以用如图所示的装罝制取乙酸乙酯.
用五点法作函数y=sinx的图象时,应描出的五个点的横坐标分别是( )