弱小的

Many animals display maternal instincts only while their offspring are young and helpless.

许多动物在其幼崽弱小无法自助时都显出了母性的本能。

Results showed that germination percentage of urediospore, uredium number and sporulation of challenge inoculation race were reduced after inoculation with weak virulent race.

试表明，弱小种诱导接种可以降低挑接种菌系的子萌发率、子堆数、。