Thousands of people took part in the work when the old temple __________.

A．would be rebuilt

B．was rebuilding

C．was being rebuilt

D．had been rebuilt

盛夏时一些耐阴的温室花卉需要放在通风良好，隐蔽度约为（）的阴凉处。

A.10%

B.20%

C.30%

D.50%