hệ sinh thái

• habit

• habitat

• ecosystem

• greenhouse

sự ô nhiễm

• environment
• pollution
• beauty
• population

habitat

• môi trường sống

• hệ sinh thái

• loài

• tuyệt chủng

sự tuyệt chủng

• pollution

• extinction

• habitat

• population

môi trường (adj)

• environment

• environmental

• environmentally

• environmentalist

bảo vệ (v)

• protect

• protector

• protection

• protective

Joey was playing the guitar .................... Danny was washing the dishes.

• while

• if

• so

• or

She had an unpleasant experience ................. she was in Thai Lan.

• when

• or

• by

• but

I lock my bicycle ____ going to class.

• before

• while

• because

• who

I bring my own lunch ____ the food in the canteen is terrible.

• unless

• while

• since

• whom