Why was China closed off to Europe prior to the Age of Imperialism?

In a citizens elect the president as head of government separately from the legislature. question 1 options: parliamentary democracy communist state presidential democracy autocratic state

1.3.3 quiz: primary and secondary sourcesquestion 4 of 102 pointsa secondary source is reliable and credible if the person who created thesource is an expert on the topic, is educated and respected in the field ofstudy, and:

What trade did europeans want most before the 1800s ivory wood slaves gold