And לכם should not be confused with לחם. They don't serve the same function in a sentence, but if you're not paying attention you could get tripped up.
Listen very closely for the k sound. It might be hard to hear if the speaker is speaking quickly, but it's there.
Why does Duolingo insist on teaching the feminine form of turtle (and spider)? In 30 years in Israel, I have never heard someone say צבה or עכבישה!
הַנִּצָּנִים נִרְאוּ בָאָרֶץ עֵת הַזָּמִיר הִגִּיעַ וְקוֹל הַתּוֹר נִשְׁמַע בְּאַרְצֵנוּ.
The flowers appear on the earth, the time of singing[a] has come, and the voice of the turtledove is heard in our land.
-- Song of Solomon 2:12