We have many clubs. _______ us soon! [ ]
A. Take
B. Join
C. Welcome
D. Play
答案:B
有一组等式:12+22+22=32,22+32+62=72,32+42+122=132,42+52+202=212…请观察它们的构成规律,用你发现的规律写出第8个等式为______.
参与肝脏吞噬作用