【简答题】变量(variable)指的是可以在数量上或质量上的 事物的属性,变量的两个基本特点是 和 。
【简答题】Ifyou had wanted to buy a record, what ?A. wouldyou buyB. hadyou boughtC. wouldyou have boughtD. ouldyou be buying
【单选题】访客对讲系统的室内分机的安装高度宜为中心距地()m。
【单选题】She ________ a model before she _______ a superstar.
【单选题】_______, everything would have been all right.
【单选题】Xiao Pei said she ______ Hainan for 3 months.
【单选题】Ifyou had been willing to pay $2.19for the gallon of milk purchased at thesupermarket but were required to payonly $1.89, you have gained
A.
a refund of $.30 from the clerk
B.
a consumer surplus amounting to$.30.
C.
excess marginal benefit of $2.19.
D.
producer surplus of $.30.
【单选题】访客对讲系统的室内分机的安装高度宜为中心距地( )米。