—As we know, planting trees is good for the environment. _______ will we plant trees on the hill?
—Maybe in two weeks.
A:How long
B:How soon
C:How often
D:How far
下列国家中与我国隔海相望的是( )
发电机和电动机的发明使人类步入电气化时代,其中电动机依据的原理是 ( )
鉴别不同种类岩石的依据是( )
①岩石的外观特征 ②岩石的分布地区 ③组成岩石物质的特性