Oh, I have got _______Mp4 as _______ birthday present.

下列因素中长江中下游平原地区由开发早期的限制因素转变为现在有利因素的是（   ）

短周期非金属元素X和Y能形成XY₂型化合物，下列有关说法正确的是（   ）

阅读下面短文，在空白处填入一个适当的词，或填入括号中所给单词的正确形式。

    In recent years,sandstorms ____(occur) in China frequently,especially in northwestern areas, ____severe influence has caused wide concern in China.

There're several reasons for this.First of all,people are cutting down trees without planting more, ____(make) some land become deserts.Another reason is ____it rains less due to the environment pollution.

    To ____(efficient) prevent sandstorms,first,we should plant more trees and grass which can keep the soil ____ being washed away.Second,more green fences should ____(build) along the desert, ____it helps to control the process of the desertification.

    Let's take action to do what we can ____(prevent) sandstorms from today.Soon the golden days we have been looking forward to ____(come).