Lǎo / shī / ràng / wǒ / men / bǎ / mā / de / dì / yī / gè / yīn / jié / dú / chéng / dì / yī / shēng

老师让我们把“妈”的第一个音节读成第一声。

The teacher asked us to pronounce the first syllable of “妈” in the first tone.