Undecided questions
could you tell me the meaning of these words plz?

毛笔 bamboo brush (a kind of pen)
一直 always
群众 the public, anyone who has never joined any politic party.
离开 leave
地道 1. native, pure; 2. underground tunnel
怎样 how
互相 (do something) each other, for example "learn from each other" means "互相学习"
原野 field, open land usually with grass.
浅显 easy to understand.
一共 total
好久 1. such a long time; 2. how long?; 3. when?

地道 authentic

other answers from Edward agreed.

毛笔 = máo-bǐ = writing brush
一直 = yī-zhí = all along
群众 = qún-zhòng = people as masses
离开 = lí-kāi = to depart, to leave
地道 = dì-dao = tunnel, causeway
怎样 = zěn-yàng = how, why
互相 = hù-xiāng = each other, mutually, mutual
原野 = yuán-yě = plain, open country
浅显 = qiǎn-xiǎn = obvious
一共 = yī-gòng = altogether
好久 = hǎo-jiǔ = quite a while