蘑菇属于大型真菌，它的地下菌丝的主要作用是： [ ]
A．吸收营养物质
B．吸收水分
C．吸收无机盐
D．固定地上部分
答案：A
A large crowd _______ wildly as the pilot _________ her plane safely in California.
A．had cheered; was landing
B．had cheered; landed
C．was cheering; had landed
D．was cheering; landed
焊件接阴极，焊条接阳极的接法称为正接法。
