激素由____(填“内”或“外”)分泌腺分泌,其中生长激素由____分泌.
中山装的袖口有三个纽扣,这三个纽扣意味着三民主义,即民族主义、民权主义、民主主义。____
— My brother hurt his legs when he rode his bike on the way back home.— ______.
某同学鉴别NH4HCO3、NH4Cl、KCl三种化肥的过程如图,其中,试剂甲和乙分别是( )