grammer 問題 15點 15.

Retail (verb) 零售 = to be sold to the public, usually in shops, for a particular price.
Sell (verb) 賣 = to give someone goods, property or services in return for money.

Selling price 銷售價 = the price at which something can be bought, or at which it has been sold (Selling price比較浮動)
Retail price零售價 = the price of something in a shop

Retail是商業的用詞, 是商店用, 小販很少用, Retail 多數指某個產品
sell 是普遍的的用詞, 比較常用. Sell有許多用法

Apple iPhone 5S retails at US $549
High-priced desktop computers sell for US $1,000 and up in that shop.

The wine sells for $100 (a bottle) ~ 漏了 for (preposition)
He is engaged in the retail business.

Engage (transitive verb) = to employ someone or to pay someone to do something for you.
You should engage a lawyer in the drafting of a contract. (active voice)

Retain (v) = 保持, (但有留住含意), retain = keep 其他意思 ~ 聘請, 記得
Maintain (v) = 保持, (可能有維修含意), 其他意思 ~ 主張, 供養

He retains all the things so that there is nothing to be changed. (不明白你這句)
She inherits the merit (good character, good look) from her mom.

3. I restrict myself to study not more than two hours every day.
3. I encourage myself to study at least two hours every day.

restrict 與 at least不協調
every day 兩個字分開寫, everyday 是adjective

My boss appoints me as a manager in this restaurant.

Hong Kong was a village in the past, but nowadays it is an international centre.
Hong Kong was a village in the past, but it has evolved into an international centre since then.

Nowadays (adverb) ~ 有 –s尾
a village - an international centre ( 要 indefinite article "an")