Though this kind of _______ has some _______, it is good enough for construction(建筑).

—How did you do in the driving test yesterday? —I had a narrow ______. My month-long practice gave me some comfort.

The rocks are very big with _____ of colors on them.

Although dragon doesn’t exist, we still take it as a _______ of our nation. 

Scientists have to work hard to keep ________ with modern discoveries and developments..