) Suggest how the learners might obtain a more representative sample of pebbles if the investigation were to be repeated.
(2)

Humans have survived and thrived in mexico city by using technology to create greater access to land. when the spanish conquered the aztec capital, tenochtitlan, in the 16th century, they built mexico city by draining the lakes and filling in the lake water to create more arable land for agriculture. this technique of land reclamation has continued to be fundamental to human civilization in mexico city. 

The zhou dynasty (1046-256 bce) was the longest-lasting of china's dynasties. it followed the shang dynasty (c. 1600-1046 bce) and it finished when the army of the state of qin captured the city of chengzhou in 256 bce.

The answers are/ (b) climate refers to long term atmospheric,conditions weather refers to short term.

Is this science or geogrpahy ? ? a little confused