Join the pairs of sentences．

(把每对句子连成一句。)

The four ancient Chinese inventions have remained important in human history for thousands of years．

We are proud of them．

Join the pairs of sentences．

(把每对句子连成一句。)

The wires were very old．

The machines were connected with them．

Join the pairs of sentences．

(把每对句子连成一句。)

The room was very dusty．

We took the photos in it．

Underline the correct word in each sentence．

(在正确的单词下画线。)

This is the reason ________(why/which)he gave for his absence．

Underline the correct word in each sentence．

(在正确的单词下画线。)

This is the reason ________(why/which)he was absent．

Underline the correct word in each sentence．

(在正确的单词下画线。)

This is the factory ________(where/which)we worked last year．

Underline the correct word in each sentence．

(在正确的单词下画线。)

This is the factory ________(where/which)we visited last year．

Underline the correct word in each sentence．

(在正确的单词下画线。)

I will never forget the days ________(when/which)we spent together．

Underline the correct word in each sentence．

(在正确的单词下画线。)

I will never forget the days ________(when/which)we lived in the country．

Match the dialogue parts．Draw a line．

(把下列对话用线连起来。)