Idon’tknowwhoinventedtelephone-优题课

I don’t know who invented ________ telephone. It’s really ________ most useful invention.

A．the; a

B．/; a

C．a; the

D．/; the

科目英语题型单选题难度中等

Pine trees, of which there are almost one hundred ____, are found throughout the North Temperate Zone.

The salmon dish was _______, wasn’t it?

The conference had been held to discuss the effects of tourism ___ the wildlife in the rainforest.

Specialists may be useful to _____ a situation and suggest solutions.

Problems _____ because they were lack of communication.